ACPI: processor_idle: Fix memory leak in acpi_processor_power_exit()

After unregistering the CPU idle device, the memory associated with
it is not freed, leading to a memory leak:

unreferenced object 0xffff896282f6c000 (size 1024):
comm "swapper/0", pid 1, jiffies 4294893170
hex dump (first 32 bytes):
00 00 00 00 0b 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 8836a742):
[<ffffffff993495ed>] kmalloc_trace+0x29d/0x340
[<ffffffff9972f3b3>] acpi_processor_power_init+0xf3/0x1c0
[<ffffffff9972d263>] __acpi_processor_start+0xd3/0xf0
[<ffffffff9972d2bc>] acpi_processor_start+0x2c/0x50
[<ffffffff99805872>] really_probe+0xe2/0x480
[<ffffffff99805c98>] __driver_probe_device+0x78/0x160
[<ffffffff99805daf>] driver_probe_device+0x1f/0x90
[<ffffffff9980601e>] __driver_attach+0xce/0x1c0
[<ffffffff99803170>] bus_for_each_dev+0x70/0xc0
[<ffffffff99804822>] bus_add_driver+0x112/0x210
[<ffffffff99807245>] driver_register+0x55/0x100
[<ffffffff9aee4acb>] acpi_processor_driver_init+0x3b/0xc0
[<ffffffff990012d1>] do_one_initcall+0x41/0x300
[<ffffffff9ae7c4b0>] kernel_init_freeable+0x320/0x470
[<ffffffff99b231f6>] kernel_init+0x16/0x1b0
[<ffffffff99042e6d>] ret_from_fork+0x2d/0x50

Fix this by freeing the CPU idle device after unregistering it.

Fixes: 3d339dcbb56d ("cpuidle / ACPI : move cpuidle_device field out of the acpi_processor_power structure")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor_idle: use raw_safe_halt() in acpi_idle_play_dead()

Xen HVM guests were observed taking triple-faults when attempting to
online a previously offlined vCPU.

Investigation showed that the fault was coming from a failing call
to lockdep_assert_irqs_disabled(), in load_current_idt() which was
too early in the CPU bringup to actually catch the exception and
report the failure cleanly.

This was a false positive, caused by acpi_idle_play_dead() setting
the per-cpu hardirqs_enabled flag by calling safe_halt(). Switch it
to use raw_safe_halt() instead, which doesn't do so.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: 6.6+ <stable@vger.kernel.org> # 6.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle, ACPI: Evaluate LPI arch_flags for broadcast timer

Arm® Functional Fixed Hardware Specification defines LPI states,
which provide an architectural context loss flags field that can
be used to describe the context that might be lost when an LPI
state is entered.

- Core context Lost
- General purpose registers.
- Floating point and SIMD registers.
- System registers, include the System register based
- generic timer for the core.
- Debug register in the core power domain.
- PMU registers in the core power domain.
- Trace register in the core power domain.
- Trace context loss
- GICR
- GICD

Qualcomm's custom CPUs preserves the architectural state,
including keeping the power domain for local timers active.
when core is power gated, the local timers are sufficient to
wake the core up without needing broadcast timer.

The patch fixes the evaluation of cpuidle arch_flags, and moves only to
broadcast timer if core context lost is defined in ACPI LPI.

Fixes: a36a7fecfe60 ("ACPI / processor_idle: Add support for Low Power Idle(LPI) states")
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Oza Pawandeep <quic_poza@quicinc.com>
Link: https://lore.kernel.org/r/20231003173333.2865323-1-quic_poza@quicinc.com
Signed-off-by: Will Deacon <will@kernel.org>

x86/smpboot: Remove the CPU0 hotplug kludge

This was introduced with commit e1c467e69040 ("x86, hotplug: Wake up CPU0
via NMI instead of INIT, SIPI, SIPI") to eventually support physical
hotplug of CPU0:

"We'll change this code in the future to wake up hard offlined CPU0 if
real platform and request are available."

11 years later this has not happened and physical hotplug is not officially
supported. Remove the cruft.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck
Link: https://lore.kernel.org/r/20230512205255.768845190@linutronix.de

cpuidle, ACPI: Make noinstr clean

objtool found cases where ACPI methods called out into instrumentation code:

vmlinux.o: warning: objtool: io_idle+0xc: call to __inb.isra.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_idle_enter+0xfe: call to num_online_cpus() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_idle_enter+0x115: call to acpi_idle_fallback_to_c1.isra.0() leaves .noinstr.text section

Fix this by: marking the IO in/out, acpi_idle_fallback_to_c1() and
num_online_cpus() methods as __always_inline.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195541.294846301@infradead.org

acpi_idle: Remove tracing

All the idle routines are called with RCU disabled, as such there must
not be any tracing inside.

While there; clean-up the io-port idle thing.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.251666856@infradead.org

cpuidle: Fix ct_idle_*() usage

The whole disable-RCU, enable-IRQS dance is very intricate since
changing IRQ state is traced, which depends on RCU.

Add two helpers for the cpuidle case that mirror the entry code:

ct_cpuidle_enter()
ct_cpuidle_exit()

And fix all the cases where the enter/exit dance was buggy.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.130014793@infradead.org

cpuidle, dt: Push RCU-idle into driver

Doing RCU-idle outside the driver, only to then temporarily enable it
again before going idle is suboptimal.

Notably: this converts all dt_init_idle_driver() and
__CPU_PM_CPU_IDLE_ENTER() users for they are inextrably intertwined.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.068981667@infradead.org

ACPI: processor: idle: Drop unnecessary (void *) conversion

The (void *) type pointer does not need to be cast, so don't do
that in lapic_timer_check_state().

Signed-off-by: Zhou jie <zhoujie@nfschina.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: idle: Drop unnecessary statements and parens

Drop a redundant "else", a "return" statement at the end of a void
function and redundant parentheses around an unsigent int variable
name from the ACPI processor idle driver.

No expected functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: idle: Check acpi_fetch_acpi_dev() return value

The return value of acpi_fetch_acpi_dev() could be NULL, which would
cause a NULL pointer dereference to occur in acpi_device_hid().

Signed-off-by: Li Zhong <floridsleeves@gmail.com>
[ rjw: Subject and changelog edits, added empty line after if () ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: move from strlcpy() with unused retval to strscpy()

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor idle: Practically limit "Dummy wait" workaround to old Intel systems

Old, circa 2002 chipsets have a bug: they don't go idle when they are
supposed to. So, a workaround was added to slow the CPU down and
ensure that the CPU waits a bit for the chipset to actually go idle.
This workaround is ancient and has been in place in some form since
the original kernel ACPI implementation.

But, this workaround is very painful on modern systems. The "inl()"
can take thousands of cycles (see Link: for some more detailed
numbers and some fun kernel archaeology).

First and foremost, modern systems should not be using this code.
Typical Intel systems have not used it in over a decade because it is
horribly inferior to MWAIT-based idle.

Despite this, people do seem to be tripping over this workaround on
AMD system today.

Limit the "dummy wait" workaround to Intel systems. Keep Modern AMD
systems from tripping over the workaround. Remotely modern Intel
systems use intel_idle instead of this code and will, in practice,
remain unaffected by the dummy wait.

Reported-by: K Prateek Nayak <kprateek.nayak@amd.com>
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lore.kernel.org/all/20220921063638.2489-1-kprateek.nayak@amd.com/
Link: https://lkml.kernel.org/r/20220922184745.3252932-1-dave.hansen@intel.com

context_tracking: Take idle eqs entrypoints over RCU

The RCU dynticks counter is going to be merged into the context tracking
subsystem. Start with moving the idle extended quiescent states
entrypoints to context tracking. For now those are dumb redirections to
existing RCU calls.

[ paulmck: Apply kernel test robot feedback. ]

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>

ACPI: processor/idle: Annotate more functions to live in cpuidle section

Commit 6727ad9e206c ("nmi_backtrace: generate one-line reports for idle cpus")
introduced a new text section called cpuidle; with that, we have a mechanism
to add idling functions in such section and skip them from nmi_backtrace
output, since they're useless and potentially flooding for such report.

Happens that inlining might cause some real idle functions to end-up
outside of such section; this is currently the case of ACPI processor_idle
driver; the functions acpi_idle_enter_* do inline acpi_idle_do_entry(),
hence they stay out of the cpuidle section.
Fix that by marking such functions to also live in the cpuidle section.

Fixes: 6727ad9e206c ("nmi_backtrace: generate one-line reports for idle cpus")
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: idle: Expose max_cstate/nocst/bm_check_disable read-only in sysfs

This will allow super users to verify the module parameters in question
when changed via kernel command line.

The parameters "nocst/bm_check_disable" are only used for enable/disable,
so change them from integer to bool.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Add perf low power callback

Add an optional callback needed by some PMU features, e.g., AMD
BRS, to give a chance to the perf_events code to change its state before
a CPU goes to low power and after it comes back.

The callback is void when the PERF_NEEDS_LOPWR_CB flag is not set.
This flag must be set in arch specific perf_event.h header whenever needed.
When not set, there is no impact on the ACPI code.

Signed-off-by: Stephane Eranian <eranian@google.com>
[peterz: build fix]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220322221517.2510440-9-eranian@google.com

Revert "ACPI: processor: idle: fix lockup regression on 32-bit ThinkPad T40"

This reverts commit bfe55a1f7fd6bfede16078bf04c6250fbca11588.

This was presumably misdiagnosed as an inability to use C3 at
all when I suspect the real problem is just misconfiguration of
C3 vs. ARB_DIS.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: 5.16+ <stable@vger.kernel.org> # 5.16+
Tested-by: Woody Suwalski <wsuwalski@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: idle: Avoid falling back to C3 type C-states

The "safe state" index is used by acpi_idle_enter_bm() to avoid
entering a C-state that may require bus mastering to be disabled
on entry in the cases when this is not going to happen. For this
reason, it should not be set to point to C3 type of C-states, because
they may require bus mastering to be disabled on entry in principle.

This was broken by commit d6b88ce2eb9d ("ACPI: processor idle: Allow
playing dead in C3 state") which inadvertently allowed the "safe
state" index to point to C3 type of C-states.

This results in a machine that won't boot past the point when it first
enters C3. Restore the correct behaviour (either demote to C1/C2, or
use C3 but also set ARB_DIS=1).

I hit this on a Fujitsu Siemens Lifebook S6010 (P3) machine.

Fixes: d6b88ce2eb9d ("ACPI: processor idle: Allow playing dead in C3 state")
Cc: 5.16+ <stable@vger.kernel.org> # 5.16+
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Woody Suwalski <wsuwalski@gmail.com>
[ rjw: Subject and changelog adjustments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Revert "ACPI: processor: idle: Only flush cache on entering C3"

Revert commit 87ebbb8c612b ("ACPI: processor: idle: Only flush cache
on entering C3") that broke the assumptions of the acpi_idle_play_dead()
callers.

Namely, the CPU cache must always be flushed in acpi_idle_play_dead(),
regardless of the target C-state that is going to be requested, because
this is likely to be part of a CPU offline procedure or preparation for
entering a system-wide sleep state and the lack of synchronization
between the CPU cache and RAM may lead to problems going forward, for
example when the CPU is brought back online.

In particular, it breaks resume from suspend-to-RAM on Lenovo ThinkPad
C13 which fails occasionally until the problematic commit is reverted.

Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor idle: Check for architectural support for LPI

When `osc_pc_lpi_support_confirmed` is set through `_OSC` and `_LPI` is
populated then the cpuidle driver assumes that LPI is fully functional.

However currently the kernel only provides architectural support for LPI
on ARM. This leads to high power consumption on X86 platforms that
otherwise try to enable LPI.

So probe whether or not LPI support is implemented before enabling LPI in
the kernel. This is done by overloading `acpi_processor_ffh_lpi_probe` to
check whether it returns `-EOPNOTSUPP`. It also means that all future
implementations of `acpi_processor_ffh_lpi_probe` will need to follow
these semantics as well.

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: idle: fix lockup regression on 32-bit ThinkPad T40

Add and ACPI idle power level limit for 32-bit ThinkPad T40.

There is a regression on T40 introduced by commit d6b88ce2, starting
with kernel 5.16:

commit d6b88ce2eb9d2698eb24451eb92c0a1649b17bb1
Author: Richard Gong <richard.gong@amd.com>
Date:   Wed Sep 22 08:31:16 2021 -0500

ACPI: processor idle: Allow playing dead in C3 state

The above patch is trying to enter C3 state during init, what is causing
a T40 system freeze. I have not found a similar issue on any other of my
32-bit machines.

The fix is to add another exception to the processor_power_dmi_table[] list.
As a result the dmesg shows as expected:

[2.155398] ACPI: IBM ThinkPad T40 detected - limiting to C2 max_cstate. Override with "processor.max_cstate=9"
[2.155404] ACPI: processor limited to max C-state 2

The fix is trivial and affects only vintage T40 systems.

Fixes: d6b88ce2eb9d ("CPI: processor idle: Allow playing dead in C3 state")
Signed-off-by: Woody Suwalski <wsuwalski@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Cc: 5.16+ <stable@vger.kernel.org> # 5.16+
[ rjw: New subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: idle: Only flush cache on entering C3

According to ACPI 6.4, Section 8.2, CPU cache flushing required on
entering the C3 power state.

Avoid flushing the cache on entering other C-states.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Use acpi_fetch_acpi_dev() instead of acpi_bus_get_device()

Modify the ACPI code to use acpi_fetch_acpi_dev() instead of
acpi_bus_get_device() where applicable.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

ACPI: processor idle: Use swap() instead of open coding it

Address the following coccicheck warning:

./drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c:914:40-41:
WARNING opportunity for swap().

by using swap() for the swapping of variable values and drop
the tmp variable that is not needed any more.

Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor idle: Allow playing dead in C3 state

When some cores are disabled on AMD platforms, the system will no longer
be able to enter suspend-to-idle s0ix.

Update to allow playing dead in C3 state so that the CPUs can enter the
deepest state on AMD platforms.

BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1708
Suggested-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Richard Gong <richard.gong@amd.com>
[ rjw: Fixed coding style ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Replace deprecated CPU-hotplug functions

The functions cpu_hotplug_begin, cpu_hotplug_done, get_online_cpus() and
put_online_cpus() have been deprecated during the CPU hotplug rework. They map
directly to cpus_write_lock(), cpus_write_unlock, cpus_read_lock() and
cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor idle: Fix up C-state latency if not ordered

Generally, the C-state latency is provided by the _CST method or
FADT, but some OEM platforms using AMD Picasso, Renoir, Van Gogh,
and Cezanne set the C2 latency greater than C3's which causes the
C2 state to be skipped.

That will block the core entering PC6, which prevents S0ix working
properly on Linux systems.

In other operating systems, the latency values are not validated and
this does not cause problems by skipping states.

To avoid this issue on Linux, detect when latencies are not an
arithmetic progression and sort them.

Link: https://gitlab.freedesktop.org/agd5f/linux/-/commit/026d186e4592c1ee9c1cb44295912d0294508725
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1230#note_712174
Suggested-by: Prike Liang <Prike.Liang@amd.com>
Suggested-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Get rid of ACPICA message printing

The ACPI_DEBUG_PRINT() and ACPI_EXCEPTION() macros are used for
message printing in the ACPICA code and they should not be used
elsewhere. Special configuration (either kernel command line or
sysfs-based) is needed to see the messages printed by them and
the format of those messages is also special and convoluted.

For this reason, replace all of the ACPI_DEBUG_PRINT() and
ACPI_EXCEPTION() instances in the ACPI processor driver with
corresponding dev_*(), acpi_handle_*() and pr_*() calls depending
on the context in which they appear.

Also drop the ACPI_PROCESSOR_COMPONENT definition that is not going
to be necessary any more.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>

ACPI: processor: idle: Drop extra prefix from pr_notice()

Drop "ACPI: " from the pr_noitice() instance in
acpi_processor_cstate_first_run_checks(), because pr_fmt() causes
that prefix to be added to the message already.

Reported-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>

ACPI: processor: Fix build when CONFIG_ACPI_PROCESSOR=m

Commit 8cdddd182bd7 ("ACPI: processor: Fix CPU0 wakeup in
acpi_idle_play_dead()") tried to fix CPU0 hotplug breakage by copying
wakeup_cpu0() + start_cpu0() logic from hlt_play_dead()//mwait_play_dead()
into acpi_idle_play_dead(). The problem is that these functions are not
exported to modules so when CONFIG_ACPI_PROCESSOR=m build fails.

The issue could've been fixed by exporting both wakeup_cpu0()/start_cpu0()
(the later from assembly) but it seems putting the whole pattern into a
new function and exporting it instead is better.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 8cdddd182bd7 ("CPI: processor: Fix CPU0 wakeup in acpi_idle_play_dead()")
Cc: <stable@vger.kernel.org> # 5.10+
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Fix CPU0 wakeup in acpi_idle_play_dead()

Commit 496121c02127 ("ACPI: processor: idle: Allow probing on platforms
with one ACPI C-state") broke CPU0 hotplug on certain systems, e.g.
I'm observing the following on AWS Nitro (e.g r5b.xlarge but other
instance types are affected as well):

# echo 0 > /sys/devices/system/cpu/cpu0/online
# echo 1 > /sys/devices/system/cpu/cpu0/online
<10 seconds delay>
-bash: echo: write error: Input/output error

In fact, the above mentioned commit only revealed the problem and did
not introduce it. On x86, to wakeup CPU an NMI is being used and
hlt_play_dead()/mwait_play_dead() loops are prepared to handle it:

/*
* If NMI wants to wake up CPU0, start CPU0.
*/
if (wakeup_cpu0())
start_cpu0();

cpuidle_play_dead() -> acpi_idle_play_dead() (which is now being called on
systems where it wasn't called before the above mentioned commit) serves
the same purpose but it doesn't have a path for CPU0. What happens now on
wakeup is:
- NMI is sent to CPU0
- wakeup_cpu0_nmi() works as expected
- we get back to while (1) loop in acpi_idle_play_dead()
- safe_halt() puts CPU0 to sleep again.

The straightforward/minimal fix is add the special handling for CPU0 on x86
and that's what the patch is doing.

Fixes: 496121c02127 ("ACPI: processor: idle: Allow probing on platforms with one ACPI C-state")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Remove the duplicated ACPI_PROCESSOR_CLASS macro

The ACPI_PROCESSOR_CLASS macro is defined in <acpi/processor.h>,
and ACPI drivers for processor already included <acpi/processor.h>,
so we can remove those duplicated ACPI_PROCESSOR_CLASS macros.

Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Fix build for ARCH_APICTIMER_STOPS_ON_C3 unset

Fix the lapic_timer_needs_broadcast() stub for
ARCH_APICTIMER_STOPS_ON_C3 unset to actually return
a value.

Fixes: aa6b43d57f99 ("ACPI: processor: Use CPUIDLE_FLAG_TIMER_STOP")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Take over RCU-idle for C3-BM idle

The C3 BusMaster idle code takes lock in a number of places, some deep
inside the ACPI code. Instead of wrapping it all in RCU_NONIDLE, have
the driver take over RCU-idle duty and avoid flipping RCU state back
and forth a lot.

( by marking 'C3 && bm_check' as RCU_IDLE, we _must_ call enter_bm() for
that combination, otherwise we'll loose RCU-idle, this requires
shuffling some code around )

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Use CPUIDLE_FLAG_TLB_FLUSHED

Make acpi_processor_idle() use the generic TLB flushing code.
This again removes RCU usage after rcu_idle_enter().

(XXX make every C3 invalidate TLBs, not just C3-BM)

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Use CPUIDLE_FLAG_TIMER_STOP

Make acpi_processor_idle use the common broadcast code, there's no
reason not to. This also removes some RCU usage after
rcu_idle_enter().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: Borislav Petkov <bp@suse.de>
Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle: ACPI: fix 'return' with no value build warning

Add return value to fix return-type build warning introduced by
commit efe9711214e6 ("cpuidle: change enter_s2idle() prototype").

Fixes: efe9711214e6 ("cpuidle: change enter_s2idle() prototype")
Signed-off-by: Neal Liu <neal.liu@mediatek.com>
[ rjw: Subject & changelog edits, make acpi_idle_enter_s2idle()
return 0 in all cases ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle: change enter_s2idle() prototype

Control Flow Integrity(CFI) is a security mechanism that disallows
changes to the original control flow graph of a compiled binary,
making it significantly harder to perform such attacks.

init_state_node() assign same function callback to different
function pointer declarations.

static int init_state_node(struct cpuidle_state *idle_state,
const struct of_device_id *matches,
struct device_node *state_node) { ...
idle_state->enter = match_id->data; ...
idle_state->enter_s2idle = match_id->data; }

Function declarations:

struct cpuidle_state { ...
int (*enter) (struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index);

void (*enter_s2idle) (struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index); };

In this case, either enter() or enter_s2idle() would cause CFI check
failed since they use same callee.

Align function prototype of enter() since it needs return value for
some use cases. The return value of enter_s2idle() is no
need currently.

Signed-off-by: Neal Liu <neal.liu@mediatek.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through # [1]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: idle: Allow probing on platforms with one ACPI C-state

It is possible for ACPI _CST to return only one ACPI C-state, for
example, when deep cstate disabled in the BIOS.

And it is better for the acpi_idle driver to probe succesfully in
this case as well for consistency.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Export acpi_processor_evaluate_cst()

The intel_idle driver will be modified to use ACPI _CST subsequently
and it will need to call acpi_processor_evaluate_cst(), so move that
function to acpi_processor.c so that it is always present (which is
required by intel_idle) and export it to modules to allow the ACPI
processor driver (which is modular) to call it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Clean up acpi_processor_evaluate_cst()

Clean up acpi_processor_evaluate_cst() in multiple ways:

* Rename current_count to last_index which matches the purpose of
the variable better.

* Consistently use acpi_handle_*() for printing messages and make
the messages cleaner.

* Drop redundant parens and braces.

* Rewrite and clarify comments.

* Rearrange checks and drop the redundant ones.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Introduce acpi_processor_evaluate_cst()

In order to separate the ACPI _CST evaluation from checks
specific to the ACPI processor driver, move the majority of
the acpi_processor_get_power_info_cst() function body to a new
function, acpi_processor_evaluate_cst(), that will extract
the C-states information from _CST output, and redefine
acpi_processor_get_power_info_cst() as a wrapper around it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor: Export function to claim _CST control

The intel_idle driver will be modified to use ACPI _CST subsequently
and it will need to notify the platform firmware of that if
acpi_gbl_FADT.cst_control is set, so add a routine for this purpose,
acpi_processor_claim_cst_control(), to acpi_processor.c (so that it
is always present which is required by intel_idle) and export it
to allow the ACPI processor driver (which is modular) to call it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: processor_idle: Skip dummy wait if kernel is in guest

In function acpi_idle_do_entry(), an ioport access is used for
dummy wait to guarantee hardware behavior. But it could trigger
unnecessary VMexit if kernel is running as guest in virtualization
environment.

If it's in virtualization environment, the deeper C state enter
operation (inb()) will trap to hypervisor. It's not needed to do
dummy wait after the inb() call. So we could just remove the
dummy io port access to avoid unnecessary VMexit.

And keep dummy io port access to maintain timing for native
environment.

Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI, x86: Add Zhaoxin processors support for NONSTOP TSC

Zhaoxin CPUs have NONSTOP TSC feature, so enable the ACPI
driver support for it.

Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "hpa@zytor.com" <hpa@zytor.com>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: "rjw@rjwysocki.net" <rjw@rjwysocki.net>
Cc: "lenb@kernel.org" <lenb@kernel.org>
Cc: David Wang <DavidWang@zhaoxin.com>
Cc: "Cooper Yan(BJ-RD)" <CooperYan@zhaoxin.com>
Cc: "Qiyuan Wang(BJ-RD)" <QiyuanWang@zhaoxin.com>
Cc: "Herry Yang(BJ-RD)" <HerryYang@zhaoxin.com>
Link: https://lkml.kernel.org/r/d1cfd937dabc44518d42038b55522c53@zhaoxin.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157

Based on 3 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [kishon] [vijay] [abraham]
[i] [kishon]@[ti] [com] this program is distributed in the hope that
it will be useful but without any warranty without even the implied
warranty of merchantability or fitness for a particular purpose see
the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [graeme] [gregory]
[gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
[kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
[hk] [hemahk]@[ti] [com] this program is distributed in the hope
that it will be useful but without any warranty without even the
implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ACPI / processor: Set P_LVL{2,3} idle state descriptions

The ACPI idle driver will fallback to using the legacy P_LVL* SystemIO
method of entering C-states if the _CST method is disabled and P_BLK is
defined. However, in this case the C2 and C3 states won't have a
description set, so the user will see "<null>" when reading the
description from sysfs.

Give each of these states a description.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Add Hygon Dhyana support

The Hygon Dhyana CPU has NONSTOP TSC feature, so enable the ACPI driver
support to it.

Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: rjw@rjwysocki.net
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: x86@kernel.org
Cc: thomas.lendacky@amd.com
Cc: lenb@kernel.org
Cc: rafael@kernel.org
Cc: linux-acpi@vger.kernel.org
Link: https://lkml.kernel.org/r/cce6ee26f4e2ebbab493433264d89d7cea661284.1537533369.git.puwen@hygon.cn

ACPI / processor: Set default C1 idle state description

The ACPI idle driver will default to ACPI_CSTATE_HALT for C1 if a _CST
object for C1 is not defined. However, the description will not be set,
so users will see "<null>" when reading the description from sysfs.

Set the C1 state description when defaulting to ACPI_CSTATE_HALT.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86/centaur: Mark TSC invariant

Centaur CPU has a constant frequency TSC and that TSC does not stop in
C-States. But because the corresponding TSC feature flags are not set for
that CPU, the TSC is treated as not constant frequency and assumed to stop
in C-States, which makes it an unreliable and unusable clock source.

Setting those flags tells the kernel that the TSC is usable, so it will
select it over HPET. The effect of this is that reading time stamps (from
kernel or user space) will be faster and more efficent.

Signed-off-by: davidwang <davidwang@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: qiyuanwang@zhaoxin.com
Cc: linux-pm@vger.kernel.org
Cc: brucechang@via-alliance.com
Cc: cooperyan@zhaoxin.com
Cc: benjaminpan@viatech.com
Link: https://lkml.kernel.org/r/1516616057-5158-1-git-send-email-davidwang@zhaoxin.com

Revert "x86/mm: Stop calling leave_mm() in idle code"

This reverts commit 43858b4f25cf0adc5c2ca9cf5ce5fdf2532941e5.

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 b956575bed91 ("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: Andy 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: 43858b4f25cf "x86/mm: Stop calling leave_mm() in idle code"
Link: http://lkml.kernel.org/r/c513bbd4e653747213e05bc7062de000bf0202a5.1509793738.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

cpuidle: Make drivers initialize polling state

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>

cpuidle: Eliminate the CPUIDLE_DRIVER_STATE_START symbol

On some architectures the first (index 0) idle state is a polling
one and it doesn't really save energy, so there is the
CPUIDLE_DRIVER_STATE_START symbol allowing some pieces of
cpuidle code to avoid using that state.

However, this makes the code rather hard to follow. It is better
to explicitly avoid the polling state, so add a new cpuidle state
flag CPUIDLE_FLAG_POLLING to mark it and make the relevant code
check that flag for the first state instead of using the
CPUIDLE_DRIVER_STATE_START symbol.

In the ACPI processor driver that cannot always rely on the state
flags (like before the states table has been set up) define
a new internal symbol ACPI_IDLE_STATE_START equivalent to the
CPUIDLE_DRIVER_STATE_START one and drop the latter.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>

PM / s2idle: Rename ->enter_freeze to ->enter_s2idle

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86/mm: Stop calling leave_mm() in idle code

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: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Nadav Amit <nadav.amit@gmail.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas 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.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/amd: Simplify AMD E400 aware idle routine

Reorganize the E400 detection now that we have everything in place:
switch the CPUs to broadcast mode after the LAPIC has been initialized
and remove the facilities that were used previously on the idle path.

Unfortunately static_cpu_has_bug() cannpt be used in the E400 idle routine
because alternatives have been applied when the actual detection happens,
so the static switching does not take effect and the test will stay
false. Use boot_cpu_has_bug() instead which is definitely an improvement
over the RDMSR and the cpumask handling.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20161209182912.2726-5-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

nmi_backtrace: generate one-line reports for idle cpus

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.com
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Tested-by: Petr 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ACPI / processor_idle: Add support for Low Power Idle(LPI) states

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: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / processor_idle: introduce ACPI_PROCESSOR_CSTATE

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: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

tags: Fix DEFINE_PER_CPU expansions

$ 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: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Rafael 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ACPI / sleep: move acpi_processor_sleep to sleep.c

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: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / processor_idle: replace PREFIX with pr_fmt

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: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Remove FSF mailing addresses

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: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / processor: constify DMI system id table

There is no need to have processor_power_dmi_table[] writeable, constify
it.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle: ACPI: do not overwrite name and description of C0

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: Thomas Schlichter <thomas.schlichter@web.de>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI/idle: Use explicit broadcast control function

Replace the clockevents_notify() call with an explicit function call.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/2653377.MSAlfA939I@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>

ACPI/processor: Use explicit broadcast control function

Replace the clockevents_notify() call with an explicit function call.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/25071624.dkenaL3SGT@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>

ACPI / idle: Implement ->enter_freeze callback routine

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

ACPI / cpuidle: Common callback routine for entering states

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: Merge acpi_idle_enter_c1() and acpi_idle_enter_simple()

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: Drop flags.bm_check tests from acpi_idle_enter_bm()

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: Clean up white space in a switch statement

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: Drop irrelevant comment from acpi_idle_enter_simple()

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: Clean up fallback to C1 checks

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: Drop unnecessary calls from ->enter callback routines

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: Drop unnecessary calls from acpi_idle_do_entry()

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle / ACPI: remove unused CPUIDLE_FLAG_TIME_INVALID

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: Len Brown <len.brown@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: avoid assigning signed errno to acpi_status

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: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle: Invert CPUIDLE_FLAG_TIME_VALID logic

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: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: fix deadlock between cpuidle_lock and cpu_hotplug.lock

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

ACPI / cpuidle: remove dev->state_count setting

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: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: fix max idle state handling with hotplug CPU support

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: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86, acpi, idle: Restructure the mwait idle routines

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: Rafael Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131212141654.616820819@infradead.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

ACPI / processor: initialize a variable to silence compiler warning

In acpi_processor_resume(), the variable resumed_bm_rld is being
used without being initialized, so initialize it.

Signed-off-by: Al Stone <al.stone@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: remove trailing whitespace

Minor cleanup: remove some extra trailing white space.

Signed-off-by: Al Stone <al.stone@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Clean up inclusions of ACPI header files

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: Lv 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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

sched, idle: Fix the idle polling state logic

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: Mike Galbraith <bitbucket@online.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: lenb@kernel.org
Cc: tglx@linutronix.de
Link: http://lkml.kernel.org/n/tip-nc03imb0etuefmzybzj7sprf@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

ACPI / processor: remove superfluous pr == NULL checks

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: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi: delete __cpuinit usage from all acpi files

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 5e427ec2d0 ("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: Paul Gortmaker <paul.gortmaker@windriver.com>

ACPI / PM: acpi_processor_suspend() can be static

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: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Move processor suspend/resume to syscore_ops

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle: remove en_core_tk_irqen flag

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: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org> # for mach-omap2/*
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle / ACPI: recover percpu ACPI processor cstate

Commit ac3ebafa81af76d6 "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: LKP project <lkp@linux.intel.com>
Reported-by: Xie ChanglongX <changlongx.xie@intel.com>
Tested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86 idle: remove mwait_idle() and "idle=mwait" cmdline param

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: Len Brown <len.brown@intel.com>
Cc: x86@kernel.org

ACPI / idle: remove usage of the statedata

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: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI / idle: pass the cpuidle_device parameter

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: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI / idle : remove pointless headers

These different headers are not needed.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI / idle: remove unused definition

The different definitions are not used anywhere in the code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI / processor: Get power info before updating the C-states

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: Thomas Schlichter <thomas.schlichter@web.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / cpuidle: Fix NULL pointer issues when cpuidle is disabled

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: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPICA: Cleanup PM_TIMER_FREQUENCY definition.

This is a cosmetic patch only. Comparison of the resulting binary showed
only line number differences.

This patch does not affect the generation of the Linux binary.
This patch decreases 13 lines of 20121114 divergence.diff.

There is updates in ACPICA for PM_TIMER_FREQUENCY macro, this patch cleans
up the usage of this macro in Linux. This patch can also reduce the source
code diff between Linux and ACPICA.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle: Measure idle state durations with monotonic clock

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: Julius Werner <jwerner@chromium.org>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle / ACPI: fix potential NULL pointer dereference

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: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle / ACPI : move cpuidle_device field out of the acpi_processor_power structure

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: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

ACPI / processor: remove unused function parameter

The 'device' parameter is not used neither in acpi_processor_power_init
and acpi_processor_power_exit. This patch removes it.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

cpuidle / ACPI : remove power from acpi_processor_cx structure

Remove the unused power field from struct struct acpi_processor_cx.

[rjw: Modified changelog.]

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

cpuilde / ACPI: remove time from acpi_processor_cx structure

Remove the time field as it is not used.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

cpuidle / ACPI: remove usage from acpi_processor_cx structure

Remove the usage field as it is not used.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

cpuidle / ACPI : remove latency_ticks from acpi_processor_cx structure

Remove the latency_ticks field as it is not used.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

ACPICA: AcpiSrc: Fix some translation issues for Linux conversion

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: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

PM / cpuidle: System resume hang fix with cpuidle

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=2

Reported-and-tested-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

ACPI: Use struct dev_pm_ops for power management in processor driver

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: Rafael J. Wysocki <rjw@sisk.pl>

ACPI / PM: Drop pm_message_t argument from device suspend callback

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: Rafael J. Wysocki <rjw@sisk.pl>

PM / ACPI: Fix suspend/resume regression caused by cpuidle cleanup.

Commit e978aa7d7d57d04eb5f88a7507c4fb98577def77 ( 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 3439a8da16bcad6b0982ece938c9f8299bb53584
(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 b04e7bdb984 )
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: Dav Hansen <dave@linux.vnet.ibm.com>
Tested-by: Preeti Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Reviewed-by: Srivatsa S Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

ACPI processor: Use safe_halt() rather than halt() in acpi_idle_play_dead()

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: Tony Luck <tony.luck@intel.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Fix unprotected smp_processor_id() in acpi_processor_cst_has_changed()

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: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Tested-by: Yong Zhang <yong.zhang0@gmail.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

idle, x86: Allow off-lined CPU to enter deeper C states

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: Boris Ostrovsky <boris.ostrovsky@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend regression)

After commit e978aa7d7d57 ("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: Tomas M. <tmezzadra@gmail.com>
Reported-and-tested-by: Ferenc Wagner <wferi@niif.hu>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cpuidle: Single/Global registration of idle states

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/2011/4/25/83

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com>
Tested-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: Split cpuidle_state structure and move per-cpu statistics fields

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: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com>
Tested-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: Move dev->last_residency update to driver enter routine; remove dev->last_state

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/2011/3/25/52

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com>
Tested-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>

locking, ACPI: Annotate c3_lock as raw

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: Thomas Gleixner <tglx@linutronix.de>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

PM QoS: Move and rename the implementation files

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: Jean Pihet <j-pihet@ti.com>
Acked-by: markgross <markgross@thegnar.org>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

x86 idle: clarify AMD erratum 400 workaround

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: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: processor_idle: delete use of NOP CPUIDLE_FLAGs

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: Len Brown <len.brown@intel.com>

ACPI, intel_idle: Cleanup idle= internal variables

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: Thomas Renninger <trenn@suse.de>
cc: x86@kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>

drivers: Replace __get_cpu_var with __this_cpu_read if not used for an address.

__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: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

acpi_idle: delete bogus data from cpuidle_state.power_usage

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: Len Brown <len.brown@intel.com>

ACPI: Remove unused #define ACPI_PROCESSOR_FILE_POWER

Looks like a left over from /proc/acpi/processor/*/power which got removed

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

gcc-4.6: ACPI: fix unused but set variables in ACPI

Some minor improvements in error handling, but overall it was mostly dead
code.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI processor: remove deprecated ACPI procfs I/F

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: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

x86: Fix keeping track of AMD C1E

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: Michal Schmidt <mschmidt@redhat.com>
LKML-Reference: <20100727165335.GA11630@aftab>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>

time: Kill off CONFIG_GENERIC_TIME

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: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

ACPI: create "processor.bm_check_disable" boot param

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=15886

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: skip checking BM_STS if the BIOS doesn't ask for it

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=15886

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: fix unused function warning

CONFIG_ACPI_PROCFS=n:

drivers/acpi/processor_idle.c:83: warning: 'us_to_pm_timer_ticks' defined but not used.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Eliminate us to pm ticks conversion in common path

acpi_enter_[simple|bm] routines does us to pm tick conversion on every
idle wakeup and the value is only used in /proc/acpi display. We can
store the time in us and convert it into pm ticks before printing instead and
avoid the conversion in the common path.

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Fix the incorrect calculation about C-state idle time

The C-state idle time is not calculated correctly, which will return the wrong
residency time in C-state. It will have the following effects:
1. The system can't choose the deeper C-state when it is idle next time.
Of course the system power is increased. E.g. On one server machine about 40W
idle power is increased.
2. The powertop shows that it will stay in C0 running state about 95% time
although the system is idle at most time.

2.6.35-rc1 regression caused-by: 2da513f582a96c053aacc2c92873978d2ea7abff
(ACPI: Minor cleanup eliminating redundant PMTIMER_TICKS to NS conversion)

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Reported-by: Yu Zhidong <zhidong.yu@intel.com>
Tested-by: Yu Zhidong <zhidong.yu@intel.com>
Acked-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Minor cleanup eliminating redundant PMTIMER_TICKS to NS conversion

acpi_enter_[simple,bm] does
idle timing in ns, convert it to timeval, then to us, then to
pmtimer_ticks and then back to ns.

This patch changes things to
idle timing in ns, convert it to us, and then to pmtimer_ticks.

Just saves an imul along this path, but makes the code cleaner.

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: acpi_idle: touch TS_POLLING only in the non-MWAIT case

commit d306ebc28649b89877a22158fe0076f06cc46f60
(ACPI: Be in TS_POLLING state during mwait based C-state entry)
fixed an important power & performance issue where ACPI c2 and c3 C-states
were clearing TS_POLLING even when using MWAIT (ACPI_STATE_FFH).
That bug had been causing us to receive redundant scheduling interrups
when we had already been woken up by MONITOR/MWAIT.

Following up on that...

In the MWAIT case, we don't have to subsequently
check need_resched(), as that c heck was there
for the TS_POLLING-clearing case.

Note that not only does the cpuidle calling function
already check need_resched() before calling us, the
low-level entry into monitor/mwait calls it twice --
guaranteeing that a write to the trigger address
can not go un-noticed.

Also, in this case, we don't have to set TS_POLLING
when we wake, because we never cleared it.

Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Venkatesh Pallipadi <venki@google.com>

ACPI: delete unused c-state promotion/demotion data strucutures

These were used before cpuidle by the native ACPI idle driver,
which tracked promotion and demotion between states.

The code was referenced by CONFIG_ACPI_PROCFS
for /proc/acpi/processor/*/power,
but as we no longer do promotion/demotion, that
reference has been a NOP since the transition.

Signed-off-by: Len Brown <len.brown@intel.com>

PM QOS update

This patch changes the string based list management to a handle base
implementation to help with the hot path use of pm-qos, it also renames
much of the API to use "request" as opposed to "requirement" that was
used in the initial implementation. I did this because request more
accurately represents what it actually does.

Also, I added a string based ABI for users wanting to use a string
interface. So if the user writes 0xDDDDDDDD formatted hex it will be
accepted by the interface. (someone asked me for it and I don't think
it hurts anything.)

This patch updates some documentation input I got from Randy.

Signed-off-by: markgross <mgross@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

ACPI: Be in TS_POLLING state during mwait based C-state entry

ACPI deep C-state entry had a long standing bug/missing feature, wherein we were sending
resched IPIs when an idle CPU is in mwait based deep C-state. Only mwait based C1 was using
the write to the monitored address to wake up mwait'ing CPU.

This patch changes the code to retain TS_POLLING bit if we are entering an mwait based
deep C-state.

The patch has been verified to reduce the number of resched IPIs in general and also
improves the performance/power on workloads with low system utilization (i.e., when mwait based
deep C-states are being used).

Fixes "netperf ~50% regression with 2.6.33-rc1, bisect to 1b9508f"
http://marc.info/?l=linux-kernel&m=126441481427331&w=4

Reported-by: Lin Ming <ming.m.lin@intel.com>
Tested-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: fix High cpu temperature with 2.6.32

Since the rewrite of the CPU idle governor in 2.6.32, two laptops have
surfaced where the BIOS advertises a C2 power state, but for some reason
this state is not functioning (as verified in both cases by powertop
before the patch in .32).

The old governor had the accidental behavior that if a non-working state
was chosen too many times, it would end up falling back to C1. The new
governor works differently and this accidental behavior is no longer
there; the result is a high temperature on these two machines.

This patch adds these 2 machines to the DMI table for C state anomalies;
by just not using C2 both these machines are better off (the TSC can be
used instead of the pm timer, giving a performance boost for example).

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=14742

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Reported-by: <akwatts@ymail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: replace acpi_integer by u64

acpi_integer is now obsolete and removed from the ACPICA code base,
replaced by u64.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: delete acpi_processor_power_verify_c2()

no functional change -- cleanup only.

acpi_processor_power_verify_c2() was nearly empty due to a previous patch,
so expand its remains into its one caller and delete it.

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: allow C3 > 1000usec

Do for C3 what the previous patch did for C2.

The C2 patch was in response to a highly visible
and multiply reported C-state/turbo failure,
while this change has no bug report in-hand.

This will enable C3 in Linux on systems where BIOS
overstates C3 latency in _CST. It will also enable
future systems which may actually have C3 > 1000usec.

Linux has always ignored ACPI BIOS C3 with exit latency > 1000 usec,
and the ACPI spec is clear that is correct FADT-supplied C3.

However, the ACPI spec explicitly states that _CST-supplied C-states
have no latency limits.

So move the 1000usec C3 test out of the code shared
by FADT and _CST code-paths, and into the FADT-specific path.

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: enable C2 and Turbo-mode on Nehalem notebooks on A/C

Linux has always ignored ACPI BIOS C2 with exit latency > 100 usec,
and the ACPI spec is clear that is correct FADT-supplied C2.

However, the ACPI spec explicitly states that _CST-supplied C-states
have no latency limits.

So move the 100usec C2 test out of the code shared
by FADT and _CST code-paths, and into the FADT-specific path.

This bug has not been visible until Nehalem, which advertises
a CPU-C2 worst case exit latency on servers of 205usec.
That (incorrect) figure is being used by BIOS writers
on mobile Nehalem systems for the AC configuration.
Thus, Linux ignores C2 leaving just C1, which is
saves less power, and also impacts performance
by preventing the use of turbo mode.

http://bugzilla.kernel.org/show_bug.cgi?id=15064

Tested-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: fix for lapic_timer_propagate_broadcast()

I got following warning on ia64 box:
In function 'acpi_processor_power_verify':
642: warning: passing argument 2 of 'smp_call_function_single' from
incompatible pointer type

This smp_call_function_single() was introduced by a commit
f833bab87fca5c3ce13778421b1365845843b976:

> @@ -162,8 +162,9 @@
> pr->power.timer_broadcast_on_state = state;
> }
>
> -static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
> +static void lapic_timer_propagate_broadcast(void *arg)
> {
> + struct acpi_processor *pr = (struct acpi_processor *) arg;
> unsigned long reason;
>
> reason = pr->power.timer_broadcast_on_state < INT_MAX ?
> @@ -635,7 +636,8 @@
> working++;
> }
>
> - lapic_timer_propagate_broadcast(pr);
> + smp_call_function_single(pr->id, lapic_timer_propagate_broadcast,
> + pr, 1);
>
> return (working);
> }

The problem is that the lapic_timer_propagate_broadcast() has 2 versions:
One is real code that modified in the above commit, and the other is NOP
code that used when !ARCH_APICTIMER_STOPS_ON_C3:

static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }

So I got warning because of !ARCH_APICTIMER_STOPS_ON_C3.

We really want to do nothing here on !ARCH_APICTIMER_STOPS_ON_C3, so
modify lapic_timer_propagate_broadcast() of real version to use
smp_call_function_single() in it.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: kill "unused variable ‘i’" warning

Commit 3d5b6fb47a8e68fa311ca2c3447e7f8a7c3a9cf3 ("ACPI: Kill overly
verbose "power state" log messages") removed the actual use of this
variable, but didn't remove the variable itself, resulting in build
warnings like

drivers/acpi/processor_idle.c: In function ‘acpi_processor_power_init’:
drivers/acpi/processor_idle.c:1169: warning: unused variable ‘i’

Just get rid of the now unused variable.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ACPI: Kill overly verbose "power state" log messages

I was recently lucky enough to get a 64-CPU system, so my kernel log
ends up with 64 lines like:

ACPI: CPU0 (power states: C1[C1] C2[C3])

This is pretty useless clutter because this info is already available
after boot from both /sys/devices/system/cpu/cpu*/cpuidle/state?/ as
well as /proc/acpi/processor/CPU*/power.

So just delete the code that prints the C-states in processor_idle.c.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Move definition of PREFIX from acpi_bus.h to internal..h

Linux/ACPI core files using internal.h all PREFIX "ACPI: ",
however, not all ACPI drivers use/want it -- and they
should not have to #undef PREFIX to define their own.

Add GPL commment to internal.h while we are there.

This does not change any actual console output,
asside from a whitespace fix.

Signed-off-by: Len Brown <len.brown@intel.com>

clockevent: Prevent dead lock on clockevents_lock

Currently clockevents_notify() is called with interrupts enabled at
some places and interrupts disabled at some other places.

This results in a deadlock in this scenario.

cpu A holds clockevents_lock in clockevents_notify() with irqs enabled
cpu B waits for clockevents_lock in clockevents_notify() with irqs disabled
cpu C doing set_mtrr() which will try to rendezvous of all the cpus.

This will result in C and A come to the rendezvous point and waiting
for B. B is stuck forever waiting for the spinlock and thus not
reaching the rendezvous point.

Fix the clockevents code so that clockevents_lock is taken with
interrupts disabled and thus avoid the above deadlock.

Also call lapic_timer_propagate_broadcast() on the destination cpu so
that we avoid calling smp_call_function() in the clockevents notifier
chain.

This issue left us wondering if we need to change the MTRR rendezvous
logic to use stop machine logic (instead of smp_call_function) or add
a check in spinlock debug code to see if there are other spinlocks
which gets taken under both interrupts enabled/disabled conditions.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: "Brown Len" <len.brown@intel.com>
LKML-Reference: <1250544899.2709.210.camel@sbs-t61.sc.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

ACPI: fix CONFIG_ACPI_PROCFS=n build warning

drivers/acpi/processor_idle.c:1162: warning: unused variable ‘entry’

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Make ACPI processor proc I/F depend on the ACPI_PROCFS

Now whether the ACPI processor proc I/F is registered depends on the
CONFIG_PROC. It had better depend on the CONFIG_ACPI_PROCFS.
When the CONFIG_ACPI_PROCFS is unset in kernel configuration, the
ACPI processor proc I/F won't be registered.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: idle: rename lapic timer workaround routines

cosmetic only. The lapic_timer workaround routines
are specific to the lapic_timer, and are not acpi-generic.

old:

acpi_timer_check_state()
acpi_propagate_timer_broadcast()
acpi_state_timer_broadcast()

new:

lapic_timer_check_state()
lapic_timer_propagate_broadcast()
lapic_timer_state_broadcast()

also, simplify the code in acpi_processor_power_verify()
so that lapic_timer_check_state() is simply called
from one place for all valid C-states, including C1.

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Disable ARB_DISABLE on platforms where it is not needed

ARB_DISABLE is a NOP on all of the recent Intel platforms.

For such platforms, reduce contention on c3_lock
by skipping the fake ARB_DISABLE.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: fix AMD C1E suspend hang

When AMD C1E is enabled, local APIC timer will stop even in C1. To avoid
suspend/resume hang, this patch removes C1 and replace it with a cpu_relax() in
suspend/resume path. This hasn't any impact in runtime path.

http://bugzilla.kernel.org/show_bug.cgi?id=13233

[ impact: avoid suspend/resume hang in AMD CPU with C1E enabled ]

Tested-by: Dmitry Lyzhyn <thisistempbox@yahoo.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: makes AMD C1E work in acpi_idle

When AMD C1E is enabled, local APIC timer will stop even in C1.
This patch uses broadcast IPI to replace local APIC timer in C1.

http://bugzilla.kernel.org/show_bug.cgi?id=13233

[ impact: avoid boot hang in AMD CPU with C1E enabled ]

Tested-by: Dmitry Lyzhyn <thisistempbox@yahoo.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Idle C-states disabled by max_cstate should not disable the TSC

Processor idle power states C2 and C3 stop the TSC on many machines.
Linux recognizes this situation and marks the TSC as unstable:

Marking TSC unstable due to TSC halts in idle

But if those same machines are booted with "processor.max_cstate=1",
then there is no need to validate C2 and C3, and no need to
disable the TSC, which can be reliably used as a clocksource.

Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>

ACPI: idle: fix init-time TSC check regression

A previous 2.6.30 patch, a71e4917dc0ebbcb5a0ecb7ca3486643c1c9a6e2,
(ACPI: idle: mark_tsc_unstable() at init-time, not run-time)
erroneously disabled the TSC on systems that did not actually
have valid deep C-states.

Move the check after the deep-C-states are validated,
via new helper, tsc_check_state(), hich replaces tsc_halts_in_c().

Signed-off-by: Len Brown <len.brown@intel.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Frans Pop <elendil@planet.nl>

ACPI: suspend: restore BM_RLD on resume

In 2.6.29,
31878dd86b7df9a147f5e6cc6e07092b4308782b
"ACPI: remove BM_RLD access from idle entry path"
moved BM_RLD initialization to init-time from run time.

But we discovered that some BIOS do not restore BM_RLD
after suspend, causing device errors on C3 and C4
after resume. So now the kernel restores BM_RLD.

http://bugzilla.kernel.org/show_bug.cgi?id=13032

Signed-off-by: Len Brown <len.brown@intel.com>

perf_counter: Remove ACPI quirk

We had a disable/enable around acpi_idle_do_entry() due to an erratum
in an early prototype CPU i had access to. That erratum has been fixed
in the BIOS so remove the quirk.

The quirk also kept us from profiling interrupts that hit the ACPI idle
instruction - so this is an improvement as well, beyond a cleanup and
a micro-optimization.

[ Impact: improve profiling scope, cleanup, micro-optimization ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

perf_counter: Rework the perf counter disable/enable

The current disable/enable mechanism is:

token = hw_perf_save_disable();
...
/* do bits */
...
hw_perf_restore(token);

This works well, provided that the use nests properly. Except we don't.

x86 NMI/INT throttling has non-nested use of this, breaking things. Therefore
provide a reference counter disable/enable interface, where the first disable
disables the hardware, and the last enable enables the hardware again.

[ Impact: refactor, simplify the PMU disable/enable logic ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

ACPI: prevent processor.max_cstate=0 boot crash

As processor.max_cstate is an init-time-only modparam,
sanity checking it at init-time is sufficient.

http://bugzilla.kernel.org/show_bug.cgi?id=13142

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI/hpet: prevent boot hang when hpet=force used on ICH-4M

Linux tells ICH4 users that they can (manually) invoke
"hpet=force" to enable the undocumented ICH-4M HPET.
The HPET becomes available for both clocksource and clockevents.

But as of ff69f2bba67bd45514923aaedbf40fe351787c59
(acpi: fix of pmtimer overflow that make Cx states time incorrect)
the HPET may be used via clocksource for idle accounting, and
hpet=force on an ICH4 box hangs boot.

It turns out that touching the MMIO HPET withing
the ARB_DIS part of C3 will hang the hardware.

The fix is to simply move the timer access outside
the ARB_DIS region. This is a no-op on modern hardware
because ARB_DIS is no longer used.

http://bugzilla.kernel.org/show_bug.cgi?id=13087

Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: delete obsolete "bus master activity" proc field

Linux-2.6.29 deleted the legacy ACPI idle handler, leaving
the CPU_IDLE handler, which does not track bus master activity.

So delete the unused bm_activity field -- it is confusing to
print an always zero value.

This patch could break programs that parse
/proc/acpi/processor/*/power, since it deletes this
line from that file:

bus master activity: 00000000

http://bugzilla.kernel.org/show_bug.cgi?id=13145
is not fixed by this patch, but provoked this patch.

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: idle: mark_tsc_unstable() at init-time, not run-time

The c2 and c3 idle handlers check tsc_halts_in_c()
after every time they return from idle. Um, when?:-)

Move this check to init-time to remove the unnecessary
run-time overhead, and also to have the check complete before
the first entry into the idle handler.

ff69f2bba67bd45514923aaedbf40fe351787c59
(acpi: fix of pmtimer overflow that make Cx states time incorrect)
replaced the hard-coded use of the PM-timer inside idle,
with ktime_get_readl(), which possibly uses the TSC --
so it is now especially prudent to detect a broken TSC
before entering idle.

http://bugzilla.kernel.org/show_bug.cgi?id=13087

Signed-off-by: Len Brown <len.brown@intel.com>

x86 ACPI: Add support for Always Running APIC timer

Add support for Always Running APIC timer, CPUID_0x6_EAX_Bit2.
This bit means the APIC timer continues to run even when CPU is
in deep C-states.

The advantage is that we can use LAPIC timer on these CPUs
always, and there is no need for "slow to read and program"
external timers (HPET/PIT) and the timer broadcast logic
and related code in C-state entry and exit.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Remove R40e c-state blacklist

The recent ACPICA patch
(ACPICA: FADT: Favor 32-bit register addresses for compatibility)
makes machine to use the right FADT HW addresses
and C-states now work fine.

http://bugzilla.kernel.org/show_bug.cgi?id=8246

Signed-off-by: Thomas Renninger <trenn@suse.de>
Tested-by: Mark Doughty <me@markdoughty.co.uk>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPICA: Rename ACPI bit register access functions

Rename acpi_get_register and acpi_set_register to clarify the
purpose of these functions. New names are acpi_read_bit_register
and acpi_write_bit_register.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPICA: Optimize ACPI register locking

Removed locking for reads from the ACPI bit registers in PM1
Status, Enable, Control, and PM2 Control. The lock is not required
when reading the single-bit registers. The acpi_get_register_unlocked
function is no longer needed and has been removed. This will
improve performance for reads on these registers. ACPICA BZ 760.

http://www.acpica.org/bugzilla/show_bug.cgi?id=760

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

acpi: fix of pmtimer overflow that make Cx states time incorrect

We found Cx states time abnormal in our some of machines which have 16
LCPUs, the C0 take too many time while system is really idle when kernel
enabled tickless and highres. powertop output is below:

PowerTOP version 1.9 (C) 2007 Intel Corporation

Cn Avg residency P-states (frequencies)
C0 (cpu running) (40.5%) 2.53 Ghz 0.0%
C1 0.0ms ( 0.0%) 2.53 Ghz 0.0%
C2 128.8ms (59.5%) 2.40 Ghz 0.0%
1.60 Ghz 100.0%

Wakeups-from-idle per second : 4.7 interval: 20.0s
no ACPI power usage estimate available

Top causes for wakeups:
41.4% ( 24.9) <interrupt> : extra timer interrupt
20.2% ( 12.2) <kernel core> : usb_hcd_poll_rh_status
(rh_timer_func)

After tacking detailed for this issue, Yakui and I find it is due to 24
bit PM timer overflows when some of cpu sleep more than 4 seconds. With
tickless kernel, the CPU want to sleep as much as possible when system
idle. But the Cx sleep time are recorded by pmtimer which length is
determined by BIOS. The current Cx time was gotten in the following
function from driver/acpi/processor_idle.c:

static inline u32 ticks_elapsed(u32 t1, u32 t2)
{
if (t2 >= t1)
return (t2 - t1);
else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
else
return ((0xFFFFFFFF - t1) + t2);
}

If pmtimer is 24 bits and it take 5 seconds from t1 to t2, in above
function, just about 1 seconds ticks was recorded. So the Cx time will be
reduced about 4 seconds. and this is why we see above powertop output.

To resolve this problem, Yakui and I use ktime_get() to record the Cx
states time instead of PM timer as the following patch. the patch was
tested with i386/x86_64 modes on several platforms.

Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Tested-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Yakui.zhao <yakui.zhao@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

perfcounters: fix acpi_idle_do_entry() workaround

Fix merge error in drivers/acpi/processor_idle.c. This
resulted in non-working perfcounters on certain Nehalem
systems.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

ACPI: delete CPU_IDLE=n code

CPU_IDLE=y has been default for ACPI=y since Nov-2007,
and has shipped in many distributions since then.

Here we delete the CPU_IDLE=n ACPI idle code, since
nobody should be using it, and we don't want to
maintain two versions.

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: remove BM_RLD access from idle entry path

It is true that BM_RLD needs to be set to enable
bus master activity to wake an older chipset (eg PIIX4) from C3.

This is contrary to the erroneous wording the ACPI 2.0, 3.0
specifications that suggests that BM_RLD is an indicator
rather than a control bit.

ACPI 1.0's correct wording should be restored in ACPI 4.0:
http://www.acpica.org/bugzilla/show_bug.cgi?id=689

But the kernel should not have to clear BM_RLD
when entering a non C3-type state just to set
it again when entering a C3-type C-state.

We should be able to set BM_RLD at boot time
and leave it alone -- removing the overhead of
accessing this IO register from the idle entry path.

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: remove locking from PM1x_STS register reads

PM1a_STS and PM1b_STS are twins that get OR'd together
on reads, and all writes are repeated to both.

The fields in PM1x_STS are single bits only,
there are no multi-bit fields.

So it is not necessary to lock PM1x_STS reads against
writes because it is impossible to read an intermediate
value of a single bit. It will either be 0 or 1,
even if a write is in progress during the read.
Reads are asynchronous to writes no matter if a lock
is used or not.

Signed-off-by: Len Brown <len.brown@intel.com>

remove linux/hardirq.h from asm-generic/local.h

While looking at reducing the amount of architecture namespace pollution
in the generic kernel, I found that asm/irq.h is included in the vast
majority of compilations on ARM (around 650 files.)

Since asm/irq.h includes a sub-architecture include file on ARM, this
causes a negative impact on the ccache's ability to re-use the build
results from other sub-architectures, so we have a desire to reduce the
dependencies on asm/irq.h.

It turns out that a major cause of this is the needless include of
linux/hardirq.h into asm-generic/local.h. The patch below removes this
include, resulting in some 250 to 300 files (around half) of the kernel
then omitting asm/irq.h.

My test builds still succeed, provided two ARM files are fixed
(arch/arm/kernel/traps.c and arch/arm/mm/fault.c) - so there may be
negative impacts for this on other architectures.

Note that x86 does not include asm/irq.h nor linux/hardirq.h in its
asm/local.h, so this patch can be viewed as bringing the generic version
into line with the x86 version.

[kosaki.motohiro@jp.fujitsu.com: add #include <linux/irqflags.h> to acpi/processor_idle.c]
[adobriyan@gmail.com: fix sparc64]
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86: support always running TSC on Intel CPUs

Impact: reward non-stop TSCs with good TSC-based clocksources, etc.

Add support for CPUID_0x80000007_Bit8 on Intel CPUs as well. This bit means
that the TSC is invariant with C/P/T states and always runs at constant
frequency.

With Intel CPUs, we have 3 classes
* CPUs where TSC runs at constant rate and does not stop n C-states
* CPUs where TSC runs at constant rate, but will stop in deep C-states
* CPUs where TSC rate will vary based on P/T-states and TSC will stop in deep
C-states.

To cover these 3, one feature bit (CONSTANT_TSC) is not enough. So, add a
second bit (NONSTOP_TSC). CONSTANT_TSC indicates that the TSC runs at
constant frequency irrespective of P/T-states, and NONSTOP_TSC indicates
that TSC does not stop in deep C-states.

CPUID_0x8000000_Bit8 indicates both these feature bit can be set.
We still have CONSTANT_TSC _set_ and NONSTOP_TSC _not_set_ on some older Intel
CPUs, based on model checks. We can use TSC on such CPUs for time, as long as
those CPUs do not support/enter deep C-states.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

perf counters: consolidate hw_perf save/restore APIs

Impact: cleanup

Rename them to better match up the usual IRQ disable/enable APIs:

hw_perf_disable_all() => hw_perf_save_disable()
hw_perf_restore_ctrl() => hw_perf_restore()

Signed-off-by: Ingo Molnar <mingo@elte.hu>

perf counters: protect them against CSTATE transitions

Impact: fix rare lost events problem

There are CPUs whose performance counters misbehave on CSTATE transitions,
so provide a way to just disable/enable them around deep idle methods.

(hw_perf_enable_all() is cheap on x86.)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

ACPI: consolidate ACPI_*_COMPONENT definitions in acpi_drivers.h

Move all the component definitions for drivers to a single shared place,
include/acpi/acpi_drivers.h.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: update the last_state acpi cpuidle reflecting actual state entered

reflect the actual state entered in dev->last_state, when actaul state entered
is different from intended one.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

acpi: trivial cleanups

Trivial cleanups for ACPI. Fix misspelling in printk(), fix mismerge,
add file header.

AK: removed file header

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

ACPI/CPUIDLE: prevent setting pm_idle to NULL

pm_idle_save resp. pm_idle_old can be NULL when the restore code in
acpi_processor_cst_has_changed() resp. cpuidle_uninstall_idle_handler()
is called. This can set pm_idle unconditinally to NULL, which causes the
kernel to panic when calling pm_idle in the x86 idle code. This was
covered by an extra check for !pm_idle in the x86 idle code, which was
removed during the x86 idle code refactoring.

Instead of restoring the pm_idle check in the x86 code prevent the
acpi/cpuidle code to set pm_idle to NULL.

Reported by: Dhaval Giani http://lkml.org/lkml/2008/7/2/309
Based on a debug patch from Ingo Molnar

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ftrace: disable tracing on acpi idle calls

The acpi idle waits calls local_irq_save and then uses mwait to go into
idle. The tracer gets reenabled at local_irq_save but does not detect that
the idle allows for wake ups.

This patch adds code to disable the tracing when acpi puts the CPU to idle.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

ACPI : Create "idle=nomwait" bootparam

"idle=nomwait" disables the use of the MWAIT
instruction from both C1 (C1_FFH) and deeper (C2C3_FFH)
C-states.

When MWAIT is unavailable, the BIOS and OS generally
negotiate to use the HALT instruction for C1,
and use IO accesses for deeper C-states.

This option is useful for power and performance
comparisons, and also to work around BIOS bugs
where broken MWAIT support is advertised.

http://bugzilla.kernel.org/show_bug.cgi?id=10807
http://bugzilla.kernel.org/show_bug.cgi?id=10914

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Li Shaohua <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

ACPI: Create "idle=halt" bootparam

"idle=halt" limits the idle loop to using
the halt instruction. No MWAIT, no IO accesses,
no C-states deeper than C1.

If something is broken in the idle code,
"idle=halt" is a less severe workaround
than "idle=poll" which disables all power savings.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

ACPI: change processors from array to per_cpu variable

Change processors from an array sized by NR_CPUS to a per_cpu variable.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

smp_call_function: get rid of the unused nonatomic/retry argument

It's never used and the comments refer to nonatomic and retry
interchangably. So get rid of it.

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

cpuidle acpi driver: fix oops on AC<->DC

cpuidle and acpi driver interaction bug with the way cpuidle_register_driver()
is called. Due to this bug, there will be oops on
AC<->DC on some systems, where they support C-states in one DC and not in AC.

The current code does
ON BOOT:
Look at CST and other C-state info to see whether more than C1 is
supported. If it is, then acpi processor_idle does a
cpuidle_register_driver() call, which internally enables the device.

ON CST change notification (AC<->DC) and on suspend-resume:
acpi driver temporarily disables device, updates the device with
any new C-states, and reenables the device.

The problem is is on boot, there are no C2, C3 states supported and we skip
the register. Later on AC<->DC, we may get a CST notification and we try
to reevaluate CST and enabled the device, without actually registering it.
This causes breakage as we try to create /sys fs sub directory, without the
parent directory which is created at register time.

Thanks to Sanjeev for reporting the problem here.
http://bugzilla.kernel.org/show_bug.cgi?id=10394

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Fix acpi_processor_idle and idle= boot parameters interaction

acpi_processor_idle and "idle=" boot parameter interaction is broken.
The problem is that, at boot time acpi driver is checking for "idle=" boot
option and not registering the acpi idle handler. But, when there is a CST
changed callback (typically when switching AC <-> battery or suspend-resume)
there are no checks for boot_option_idle_override and acpi idle handler tries
to get installed with nasty side effects.

With CPU_IDLE configured this issue causes results in a nasty oops on CST
change callback and without CPU_IDLE there is no oops, but boot option
of "idle=" gets ignored and acpi idle handler gets installed.

Change the behavior to not do anything in acpi idle handler when there is a
"idle=" boot option.

Note that the problem is only there when "idle=" boot option is used.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

acpi: use non-racy method for proc entries creation

Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Add correct ->owner to proc_fops to fix reading/module unloading race.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fix idle (arch, acpi and apm) and lockdep

OK, so 25-mm1 gave a lockdep error which made me look into this.

The first thing that I noticed was the horrible mess; the second thing I
saw was hacks like: 71e93d15612c61c2e26a169567becf088e71b8ff

The problem is that arch idle routines are somewhat inconsitent with
their IRQ state handling and instead of fixing _that_, we go paper over
the problem.

So the thing I've tried to do is set a standard for idle routines and
fix them all up to adhere to that. So the rules are:

idle routines are entered with IRQs disabled
idle routines will exit with IRQs enabled

Nearly all already did this in one form or another.

Merge the 32 and 64 bit bits so they no longer have different bugs.

As for the actual lockdep warning; __sti_mwait() did a plainly un-annotated
irq-enable.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2.6.25 regression: powertop says 120K wakeups/sec

Patch to fix huge number of wakeups reported due to recent changes in
processor_idle.c. The problem was that the entry_method determination was
broken due to one of the recent commits (bc71bec91f987) causing
C1 entry to not to go to halt.

http://lkml.org/lkml/2008/3/22/124

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: fix 100% C0 statistics regression

commit 9b12e18cdc1553de62d931e73443c806347cd974
'ACPI: cpuidle: Support C1 idle time accounting'
was implicated in a 100% C0 idle regression.
http://bugzilla.kernel.org/show_bug.cgi?id=10076

It pointed out a potential problem where the menu governor
may get confused by the C-state residency time from poll
idle or C1 idle, where this timing info is not accurate.
This inaccuracy is due to interrupts being handled
before we account for C-state exit.

Do not mark TIME_VALID for CO poll state.
Mark C1 time as valid only with the MWAIT (CSTATE_FFH) entry method.

This makes governors use the timing information only when it is correct and
eliminates any wrong policy decisions that may result from invalid timing
information.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: fix mis-merge -- invoke acpi_unlazy_tlb() only on C3 entry

This original patch
http://ussg.iu.edu/hypermail/linux/kernel/0712.2/1451.html
was intending to add acpi_unlazy_tlb() to acpi_idle_enter_bm(),
which is used for C3 entry.

But it was merged incorrectly as commmit

bde6f5f59c2b2b48a7a849c129d5b48838fe77ee
'x86: voluntary leave_mm before entering ACPI C3'

so the call was instead added to acpi_idle_enter_simple()
(which is C2 entry routine), probably due to identical
context in that function.

Move the call back to acpi_idle_enter_bm().

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: lockdep warning on boot, 2.6.25-rc5

This avoids the harmless WARNING by lockdep in acpi_processor_idle().

The reason for WARNING is because at the depth of idle handling code,
some of the idle handlers disable interrupts, some times, while returning from
the idle handler. After return, acpi_processor_idle and few other routines
in the file did an unconditional local_irq_enable(). With LOCKDEP, enabling
irq when it is already enabled generates the below WARNING.

> > [ 0.593038] ------------[ cut here ]------------
> > [ 0.593267] WARNING: at kernel/lockdep.c:2035 trace_hardirqs_on+0xa0/0x115()
> > [ 0.593596] Modules linked in:
> > [ 0.593756] Pid: 0, comm: swapper Not tainted 2.6.25-rc5 #8
> > [ 0.594017]
> > [ 0.594017] Call Trace:
> > [ 0.594216] [<ffffffff80231663>] warn_on_slowpath+0x58/0x6b
> > [ 0.594495] [<ffffffff80495966>] ? _spin_unlock_irqrestore+0x38/0x47
> > [ 0.594809] [<ffffffff80329a86>] ? acpi_os_release_lock+0x9/0xb
> > [ 0.595103] [<ffffffff80337840>] ? acpi_set_register+0x161/0x173
> > [ 0.595401] [<ffffffff8034c8d4>] ? acpi_processor_idle+0x1de/0x546
> > [ 0.595706] [<ffffffff8020a23b>] ? default_idle+0x0/0x73
> > [ 0.595970] [<ffffffff8024fc0e>] trace_hardirqs_on+0xa0/0x115
> > [ 0.596049] [<ffffffff8034c6f6>] ? acpi_processor_idle+0x0/0x546
> > [ 0.596346] [<ffffffff8034c8d4>] acpi_processor_idle+0x1de/0x546
> > [ 0.596642] [<ffffffff8020a23b>] ? default_idle+0x0/0x73
> > [ 0.596912] [<ffffffff8034c6f6>] ? acpi_processor_idle+0x0/0x546
> > [ 0.597209] [<ffffffff8020a23b>] ? default_idle+0x0/0x73
> > [ 0.597472] [<ffffffff8020a355>] cpu_idle+0xa7/0xd1
> > [ 0.597717] [<ffffffff80485fa1>] rest_init+0x55/0x57
> > [ 0.597957] [<ffffffff8062fb49>] start_kernel+0x29d/0x2a8
> > [ 0.598215] [<ffffffff8062f1da>] _sinittext+0x1da/0x1e1
> > [ 0.598464]
> > [ 0.598546] ---[ end trace 778e504de7e3b1e3 ]---

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: TSC breaks atkbd suspend

TSC is used even on machines when CONFIG_X86_TSC is not set (X86_TSC
means _require_ TSC), but it is not properly disabled when it is
unusable, because ACPI code understood the config switch as "may use
TSC".

This actually fixes suspend problems on my x60.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI, cpuidle: Clarify C-state description in sysfs

Add a new sysfs entry under cpuidle states. desc - can be used by driver to
communicate to userspace any specific information about the state.
This helps in identifying the exact hardware C-states behind the ACPI C-state
definition.

Idea is to export this through powertop, which will help to map the C-state
reported by powertop to actual hardware C-state.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: fix suspend regression due to idle update

Earlier patch (bc71bec91f9875ef825d12104acf3bf4ca215fa4) broke
suspend resume on many laptops. The problem was reported by
Carlos R. Mafra and Calvin Walton, who bisected the issue to above patch.

The problem was because, C2 and C3 code were calling acpi_idle_enter_c1
directly, with C2 or C3 as state parameter, while suspend/resume was in
progress. The patch bc71bec started making use of that state information,
assuming that it would always be referring to C1 state. This caused the
problem with suspend-resume as we ended up using C2/C3 state indirectly.

Fix this by adding acpi_idle_suspend check in enter_c1.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: Add a poll_idle method

Add a default poll idle state with 0 latency. Provides an option to users
to use poll_idle by using 0 as the latency requirement.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: cpuidle: Support C1 idle time accounting

Show C1 idle time in /sysfs cpuidle interface. C1 idle time may not
be entirely accurate in all cases. It includes the time spent
in the interrupt handler after wakeup with "hlt" based C1. But, it will
be accurate with "mwait" based C1.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: enable MWAIT for C1 idle

Add MWAIT idle for C1 state instead of halt, on platforms that support
C1 state with MWAIT.

Renames cx->space_id to something more appropriate.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: idle: Fix acpi_safe_halt usages and interrupt enabling/disabling

acpi_safe_halt() needs interrupts to be disabled for atomic
need_resched check and safe halt. Otherwise we may miss an
interrupt and go into halt.

acpi_safe_halt() also does not enable interrupts on all return paths.

So the callers should handle enable and disable interrupts around it.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

latency.c: use QoS infrastructure

Replace latency.c use with pm_qos_params use.

Signed-off-by: mark gross <mgross@linux.intel.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86: don't disable TSC in any C states on AMD Fam10h

The ACPI code currently disables TSC use in any C2 and C3
states. But the AMD Fam10h BKDG documents that the TSC
will never stop in any C states when the CONSTANT_TSC bit is
set. Make this disabling conditional on CONSTANT_TSC
not set on AMD.

I actually think this is true on Intel too for C2 states
on CPUs with p-state invariant TSC, but this needs
further discussions with Len to really confirm :-)

So far it is only enabled on AMD.

Cc: lenb@kernel.org

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86: voluntary leave_mm before entering ACPI C3

Aviod TLB flush IPIs during C3 states by voluntary leave_mm()
before entering C3.

The performance impact of TLB flush on C3 should not be significant with
respect to C3 wakeup latency. Also, CPUs tend to flush TLB in hardware while in
C3 anyways.

On a 8 logical CPU system, running make -j2, the number of tlbflush IPIs goes
down from 40 per second to ~ 0. Total number of interrupts during the run
of this workload was ~1200 per second, which makes it ~3% savings in wakeups.

There was no measurable performance or power impact however.

[ akpm@linux-foundation.org: symbol export fixes. ]

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

ACPI: Reintroduce run time configurable max_cstate for !CPU_IDLE case

This was writeable in 2.6.23 but the cpuidle merge made it read-only. But
some people's scripts (ie: Mark's) were writing to it.

As an unhappy compromise, make max_cstate writeable again if the kernel was
configured without CONFIG_CPU_IDLE.

http://bugzilla.kernel.org/show_bug.cgi?id=9683

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Mark Lord <lkml@rtr.ca>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: default processor.latency_factor=2

More aggressively request deep C-states.

Note that the job of the OS is to minimize latency
impact to expected break events such as interrupts.

It is not the job of the OS to try to calculate if
the C-state will reach energy break-even.
The platform doesn't give the OS enough information
for it to make that calculation. Thus, it is up
to the platform to decide if it is worth it to
go as deep as the OS requested it to, or if it
should internally demote to a more shallow C-state.

But the converse is not true. The platform can not
promote into a deeper C-state than the OS requested
else it may violate latency constraints. So it is
important that the OS be aggressive in giving the
platform permission to enter deep C-states.

Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: create processor.latency_factor tunable

Start with default value of 6, so by default,
there is no functional change in this patch.

Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: move timer broadcast before busmaster disable

The timer broadcast code might access HPET, which should not be
accessed after the busmaster disable.

In acpi_idle_enter_simple() this change also prevents, that we modify
the busmaster state without going actually idle. This might leave the
ACPI bm state in a stale state, when we leave the function early in
the need_resched() check.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>

ACPI: Set max_cstate to 1 for early Opterons.

AMD Opteron processors before CG revision don't like C-states > 1.

This solves the long standing bugzilla #5303 and probably some more
on affected machines:

http://bugzilla.kernel.org/show_bug.cgi?id=5303

[ tglx@linutronix.de: reworked the patch so it does not wreck ia64 ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

cpuidle: fix HP nx6125 regression

Fix for http://bugzilla.kernel.org/show_bug.cgi?id=9355

cpuidle always used to fallback to C2 if there is some bm activity while
entering C3. But, presence of C2 is not always guaranteed. Change cpuidle
algorithm to detect a safe_state to fallback in case of bm_activity and
use that state instead of C2.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: add sched_clock_idle_[sleep|wakeup]_event() hooks

Port 2aa44d0567ed21b47b87d68819415d48194cb923
(sched: sched_clock_idle_[sleep|wakeup]_event()) to cpuidle.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: fix C3 for no bus-master control case

Port 18eab8550397f1f3d4b8b2c5257c88dae25d58ed
(Enable C3 even when PM2_control is zero) to cpuidle.

Without this patch, some systems will notice a regression
when enabling CPU_IDLE -- C3 would no longer be available.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: remove the now unused ifdef code

The conversion of x86-64 to clock events makes the
#ifdef CONFIG_GENERIC_CLOCKEVENTS
n the timer broadcast functions useless. Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

ACPI: cpuidle: port idle timer suspend/resume workaround to cpuidle

Some timers stop during C2 and C3, and so there are various
generations of timer broadcast workarounds to deal with that.
But that (already complex) code gets confused during suspend.

As it is unlikely that deep C-states would save much power
during the actual suspend/resume process anyway, deep C-states
were disabled via the addition of .suspend/.resume hooks
in to the ACPI processor driver.

Here that workaround is ported to the cpuidle version of
the ACPI idle loop. Technically, ACPI could un-register
itself from cpuidle on .suspend, but that code path
is currently quite cumbersome. So instead,
we simply invoke C1 from the C2 and C3 handlers
for the duration of .suspend/.resume.

Signed-off-by: Len Brown <len.brown@intel.com>

cpuidle: consolidate 2.6.22 cpuidle branch into one patch

commit e5a16b1f9eec0af7cfa0830304b41c1c0833cf9f
Author: Len Brown <len.brown@intel.com>
Date: Tue Oct 2 23:44:44 2007 -0400

cpuidle: shrink diff

processor_idle.c | 440 +++++++++++++++++++++++++++++++++++++++++--
1 file changed, 429 insertions(+), 11 deletions(-)

Signed-off-by: Len Brown <len.brown@intel.com>

commit dfbb9d5aedfb18848a3e0d6f6e3e4969febb209c
Author: Len Brown <len.brown@intel.com>
Date: Wed Sep 26 02:17:55 2007 -0400

cpuidle: reduce diff size

Reduces the cpuidle processor_idle.c diff vs 2.6.22 from this
processor_idle.c | 2006 ++++++++++++++++++++++++++-----------------
1 file changed, 1219 insertions(+), 787 deletions(-)

to this:
processor_idle.c | 502 +++++++++++++++++++++++++++++++++++++++----
1 file changed, 458 insertions(+), 44 deletions(-)

...for the purpose of making the cpuilde patch less invasive
and easier to review.

no functional changes. build tested only.

Signed-off-by: Len Brown <len.brown@intel.com>

commit 889172fc915f5a7fe20f35b133cbd205ce69bf6c
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Sep 13 13:40:05 2007 -0700

cpuidle: Retain old ACPI policy for !CONFIG_CPU_IDLE

Retain the old policy in processor_idle, so that when CPU_IDLE is not
configured, old C-state policy will still be used. This provides a
clean gradual migration path from old ACPI policy to new cpuidle
based policy.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 9544a8181edc7ecc33b3bfd69271571f98ed08bc
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Sep 13 13:39:17 2007 -0700

cpuidle: Configure governors by default

Quoting Len "Do not give an option to users to shoot themselves in the foot".

Remove the configurability of ladder and menu governors as they are
needed for default policy of cpuidle. That way users will not be able to
have cpuidle without any policy loosing all C-state power savings.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 8975059a2c1e56cfe83d1bcf031bcf4cb39be743
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:27:07 2007 -0400

CPUIDLE: load ACPI properly when CPUIDLE is disabled

Change the registration return codes for when CPUIDLE
support is not compiled into the kernel. As a result, the ACPI
processor driver will load properly even if CPUIDLE is unavailable.
However, it may be possible to cleanup the ACPI processor driver further
and eliminate some dead code paths.

Signed-off-by: Adam Belay <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit e0322e2b58dd1b12ec669bf84693efe0dc2414a8
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:26:06 2007 -0400

CPUIDLE: remove cpuidle_get_bm_activity()

Remove cpuidle_get_bm_activity() and updates governors
accordingly.

Signed-off-by: Adam Belay <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 18a6e770d5c82ba26653e53d240caa617e09e9ab
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:25:58 2007 -0400

CPUIDLE: max_cstate fix

Currently max_cstate is limited to 0, resulting in no idle processor
power management on ACPI platforms. This patch restores the value to
the array size.

Signed-off-by: Adam Belay <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 1fdc0887286179b40ce24bcdbde663172e205ef0
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:25:40 2007 -0400

CPUIDLE: handle BM detection inside the ACPI Processor driver

Update the ACPI processor driver to detect BM activity and
limit state entry depth internally, rather than exposing such
requirements to CPUIDLE. As a result, CPUIDLE can drop this
ACPI-specific interface and become more platform independent. BM
activity is now handled much more aggressively than it was in the
original implementation, so some testing coverage may be needed to
verify that this doesn't introduce any DMA buffer under-run issues.

Signed-off-by: Adam Belay <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 0ef38840db666f48e3cdd2b769da676c57228dd9
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:25:14 2007 -0400

CPUIDLE: menu governor updates

Tweak the menu governor to more effectively handle non-timer
break events. Non-timer break events are detected by comparing the
actual sleep time to the expected sleep time. In future revisions, it
may be more reliable to use the timer data structures directly.

Signed-off-by: Adam Belay <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit bb4d74fca63fa96cf3ace644b15ae0f12b7df5a1
Author: Adam Belay <abelay@novell.com>
Date: Tue Aug 21 18:24:40 2007 -0400

CPUIDLE: fix 'current_governor' sysfs entry

Allow the "current_governor" sysfs entry to properly handle
input terminated with '\n'.

Signed-off-by: Adam Belay <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit df3c71559bb69b125f1a48971bf0d17f78bbdf47
Author: Len Brown <len.brown@intel.com>
Date: Sun Aug 12 02:00:45 2007 -0400

cpuidle: fix IA64 build (again)

Signed-off-by: Len Brown <len.brown@intel.com>

commit a02064579e3f9530fd31baae16b1fc46b5a7bca8
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Sun Aug 12 01:39:27 2007 -0400

cpuidle: Remove support for runtime changing of max_cstate

Remove support for runtime changeability of max_cstate. Drivers can use
use latency APIs.

max_cstate can still be used as a boot time option and dmi override.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 0912a44b13adf22f5e3f607d263aed23b4910d7e
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Sun Aug 12 01:39:16 2007 -0400

cpuidle: Remove ACPI cstate_limit calls from ipw2100

ipw2100 already has code to use accetable_latency interfaces to limit the
C-state. Remove the calls to acpi_set_cstate_limit and acpi_get_cstate_limit
as they are redundant.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit c649a76e76be6bff1fd770d0a775798813a3f6e0
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Sun Aug 12 01:35:39 2007 -0400

cpuidle: compile fix for pause and resume functions

Fix the compilation failure when cpuidle is not compiled in.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Adam Belay <adam.belay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 2305a5920fb8ee6ccec1c62ade05aa8351091d71
Author: Adam Belay <abelay@novell.com>
Date: Thu Jul 19 00:49:00 2007 -0400

cpuidle: re-write

Some portions have been rewritten to make the code cleaner and lighter
weight. The following is a list of changes:

1.) the state name is now included in the sysfs interface
2.) detection, hotplug, and available state modifications are handled by
CPUIDLE drivers directly
3.) the CPUIDLE idle handler is only ever installed when at least one
cpuidle_device is enabled and ready
4.) the menu governor BM code no longer overflows
5.) the sysfs attributes are now printed as unsigned integers, avoiding
negative values
6.) a variety of other small cleanups

Also, Idle drivers are no longer swappable during runtime through the
CPUIDLE sysfs inteface. On i386 and x86_64 most idle handlers (e.g.
poll, mwait, halt, etc.) don't benefit from an infrastructure that
supports multiple states, so I think using a more general case idle
handler selection mechanism would be cleaner.

Signed-off-by: Adam Belay <abelay@novell.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit df25b6b56955714e6e24b574d88d1fd11f0c3ee5
Author: Len Brown <len.brown@intel.com>
Date: Tue Jul 24 17:08:21 2007 -0400

cpuidle: fix IA64 buid

Signed-off-by: Len Brown <len.brown@intel.com>

commit fd6ada4c14488755ff7068860078c437431fbccd
Author: Adrian Bunk <bunk@stusta.de>
Date: Mon Jul 9 11:33:13 2007 -0700

cpuidle: static

make cpuidle_replace_governor() static

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit c1d4a2cebcadf2429c0c72e1d29aa2a9684c32e0
Author: Adrian Bunk <bunk@stusta.de>
Date: Tue Jul 3 00:54:40 2007 -0400

cpuidle: static

This patch makes the needlessly global struct menu_governor static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit dbf8780c6e8d572c2c273da97ed1cca7608fd999
Author: Andrew Morton <akpm@linux-foundation.org>
Date: Tue Jul 3 00:49:14 2007 -0400

export symbol tick_nohz_get_sleep_length

ERROR: "tick_nohz_get_sleep_length" [drivers/cpuidle/governors/menu.ko] undefined!
ERROR: "tick_nohz_get_idle_jiffies" [drivers/cpuidle/governors/menu.ko] undefined!

And please be sure to get your changes to core kernel suitably reviewed.

Cc: Adam Belay <abelay@novell.com>
Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 29f0e248e7017be15f99febf9143a2cef00b2961
Author: Andrew Morton <akpm@linux-foundation.org>
Date: Tue Jul 3 00:43:04 2007 -0400

tick.h needs hrtimer.h

It uses hrtimers.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit e40cede7d63a029e92712a3fe02faee60cc38fb4
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:40:34 2007 -0400

cpuidle: first round of documentation updates

Documentation changes based on Pavel's feedback.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 83b42be2efece386976507555c29e7773a0dfcd1
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:39:25 2007 -0400

cpuidle: add rating to the governors and pick the one with highest rating by default

Introduce a governor rating scheme to pick the right governor by default.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit d2a74b8c5e8f22def4709330d4bfc4a29209b71c
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:38:08 2007 -0400

cpuidle: make cpuidle sysfs driver governor switch off by default

Make default cpuidle sysfs to show current_governor and current_driver in
read-only mode. More elaborate available_governors and available_drivers with
writeable current_governor and current_driver interface only appear with
"cpuidle_sysfs_switch" boot parameter.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 1f60a0e80bf83cf6b55c8845bbe5596ed8f6307b
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:37:00 2007 -0400

cpuidle: menu governor: change the early break condition

Change the C-state early break out algorithm in menu governor.

We only look at early breakouts that result in wakeups shorter than idle
state's target_residency. If such a breakout is frequent enough, eliminate
the particular idle state upto a timeout period.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 45a42095cf64b003b4a69be3ce7f434f97d7af51
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:35:38 2007 -0400

cpuidle: fix uninitialized variable in sysfs routine

Fix the uninitialized usage of ret.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 80dca7cdba3e6ee13eae277660873ab9584eb3be
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:34:16 2007 -0400

cpuidle: reenable /proc/acpi//power interface for the time being

Keep /proc/acpi/processor/CPU*/power around for a while as powertop depends
on it. It will be marked deprecated and removed in future. powertop can use
cpuidle interfaces instead.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 589c37c2646c5e3813a51255a5ee1159cb4c33fc
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Jul 3 00:32:37 2007 -0400

cpuidle: menu governor and hrtimer compile fix

Compile fix for menu governor.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 0ba80bd9ab3ed304cb4f19b722e4cc6740588b5e
Author: Len Brown <len.brown@intel.com>
Date: Thu May 31 22:51:43 2007 -0400

cpuidle: build fix - cpuidle vs ipw2100 module

ERROR: "acpi_set_cstate_limit" [drivers/net/wireless/ipw2100.ko] undefined!

Signed-off-by: Len Brown <len.brown@intel.com>

commit d7d8fa7f96a7f7682be7c6cc0cc53fa7a18c3b58
Author: Adam Belay <abelay@novell.com>
Date: Sat Mar 24 03:47:07 2007 -0400

cpuidle: add the 'menu' governor

Here is my first take at implementing an idle PM governor that takes
full advantage of NO_HZ. I call it the 'menu' governor because it
considers the full list of idle states before each entry.

I've kept the implementation fairly simple. It attempts to guess the
next residency time and then chooses a state that would meet at least
the break-even point between power savings and entry cost. To this end,
it selects the deepest idle state that satisfies the following
constraints:
1. If the idle time elapsed since bus master activity was detected
is below a threshold (currently 20 ms), then limit the selection
to C2-type or above.
2. Do not choose a state with a break-even residency that exceeds
the expected time remaining until the next timer interrupt.
3. Do not choose a state with a break-even residency that exceeds
the elapsed time between the last pair of break events,
excluding timer interrupts.

This governor has an advantage over "ladder" governor because it
proactively checks how much time remains until the next timer interrupt
using the tick infrastructure. Also, it handles device interrupt
activity more intelligently by not including timer interrupts in break
event calculations. Finally, it doesn't make policy decisions using the
number of state entries, which can have variable residency times (NO_HZ
makes these potentially very large), and instead only considers sleep
time deltas.

The menu governor can be selected during runtime using the cpuidle sysfs
interface like so:
"echo "menu" > /sys/devices/system/cpu/cpuidle/current_governor"

Signed-off-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit a4bec7e65aa3b7488b879d971651cc99a6c410fe
Author: Adam Belay <abelay@novell.com>
Date: Sat Mar 24 03:47:03 2007 -0400

cpuidle: export time until next timer interrupt using NO_HZ

Expose information about the time remaining until the next
timer interrupt expires by utilizing the dynticks infrastructure.
Also modify the main idle loop to allow dynticks to handle
non-interrupt break events (e.g. DMA). Finally, expose sleep ticks
information to external code. Thomas Gleixner is responsible for much
of the code in this patch. However, I've made some additional changes,
so I'm probably responsible if there are any bugs or oversights :)

Signed-off-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 2929d8996fbc77f41a5ff86bb67cdde3ca7d2d72
Author: Adam Belay <abelay@novell.com>
Date: Sat Mar 24 03:46:58 2007 -0400

cpuidle: governor API changes

This patch prepares cpuidle for the menu governor. It adds an optional
stage after idle state entry to give the governor an opportunity to
check why the state was exited. Also it makes sure the idle loop
returns after each state entry, allowing the appropriate dynticks code
to run.

Signed-off-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 3a7fd42f9825c3b03e364ca59baa751bb350775f
Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Apr 26 00:03:59 2007 -0700

cpuidle: hang fix

Prevent hang on x86-64, when ACPI processor driver is added as a module on
a system that does not support C-states.

x86-64 expects all idle handlers to enable interrupts before returning from
idle handler. This is due to enter_idle(), exit_idle() races. Make
cpuidle_idle_call() confirm to this when there is no pm_idle_old.

Also, cpuidle look at the return values of attch_driver() and set
current_driver to NULL if attach fails on all CPUs.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 4893339a142afbd5b7c01ffadfd53d14746e858e
Author: Shaohua Li <shaohua.li@intel.com>
Date: Thu Apr 26 10:40:09 2007 +0800

cpuidle: add support for max_cstate limit

With CPUIDLE framework, the max_cstate (to limit max cpu c-state)
parameter is ingored. Some systems require it to ignore C2/C3
and some drivers like ipw require it too.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 43bbbbe1cb998cbd2df656f55bb3bfe30f30e7d1
Author: Shaohua Li <shaohua.li@intel.com>
Date: Thu Apr 26 10:40:13 2007 +0800

cpuidle: add cpuidle_fore_redetect_devices API

add cpuidle_force_redetect_devices API,
which forces all CPU redetect idle states.
Next patch will use it.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit d1edadd608f24836def5ec483d2edccfb37b1d19
Author: Shaohua Li <shaohua.li@intel.com>
Date: Thu Apr 26 10:40:01 2007 +0800

cpuidle: fix sysfs related issue

Fix the cpuidle sysfs issue.
a. make kobject dynamicaly allocated
b. fixed sysfs init issue to avoid suspend/resume issue

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 7169a5cc0d67b263978859672e86c13c23a5570d
Author: Randy Dunlap <randy.dunlap@oracle.com>
Date: Wed Mar 28 22:52:53 2007 -0400

cpuidle: 1-bit field must be unsigned

A 1-bit bitfield has no room for a sign bit.
drivers/cpuidle/governors/ladder.c:54:16: error: dubious bitfield without explicit `signed' or `unsigned'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 4658620158dc2fbd9e4bcb213c5b6fb5d05ba7d4
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Wed Mar 28 22:52:41 2007 -0400

cpuidle: fix boot hang

Patch for cpuidle boot hang reported by Larry Finger here.
http://www.ussg.iu.edu/hypermail/linux/kernel/0703.2/2025.html

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Larry Finger <larry.finger@lwfinger.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit c17e168aa6e5fe3851baaae8df2fbc1cf11443a9
Author: Len Brown <len.brown@intel.com>
Date: Wed Mar 7 04:37:53 2007 -0500

cpuidle: ladder does not depend on ACPI

build fix for CONFIG_ACPI=n

In file included from drivers/cpuidle/governors/ladder.c:21:
include/acpi/processor.h:88: error: expected specifier-qualifier-list before ‘acpi_integer’
include/acpi/processor.h:106: error: expected specifier-qualifier-list before ‘acpi_integer’
include/acpi/processor.h:168: error: expected specifier-qualifier-list before ‘acpi_handle’

Signed-off-by: Len Brown <len.brown@intel.com>

commit 8c91d958246bde68db0c3f0c57b535962ce861cb
Author: Adrian Bunk <bunk@stusta.de>
Date: Tue Mar 6 02:29:40 2007 -0800

cpuidle: make code static

This patch makes the following needlessly global code static:
- driver.c: __cpuidle_find_driver()
- governor.c: __cpuidle_find_governor()
- ladder.c: struct ladder_governor

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Adam Belay <abelay@novell.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 0c39dc3187094c72c33ab65a64d2017b21f372d2
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Wed Mar 7 02:38:22 2007 -0500

cpu_idle: fix build break

This patch fixes a build breakage with !CONFIG_HOTPLUG_CPU and
CONFIG_CPU_IDLE.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 8112e3b115659b07df340ef170515799c0105f82
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Tue Mar 6 02:29:39 2007 -0800

cpuidle: build fix for !CPU_IDLE

Fix the compile issues when CPU_IDLE is not configured.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Adam Belay <abelay@novell.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 1eb4431e9599cd25e0d9872f3c2c8986821839dd
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Feb 22 13:54:57 2007 -0800

cpuidle take2: Basic documentation for cpuidle

Documentation for cpuidle infrastructure

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Adam Belay <abelay@novell.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit ef5f15a8b79123a047285ec2e3899108661df779
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Feb 22 13:54:03 2007 -0800

cpuidle take2: Hookup ACPI C-states driver with cpuidle

Hookup ACPI C-states onto generic cpuidle infrastructure.

drivers/acpi/procesor_idle.c is now a ACPI C-states driver that registers as
a driver in cpuidle infrastructure and the policy part is removed from
drivers/acpi/processor_idle.c. We use governor in cpuidle instead.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>

commit 987196fa82d4db52c407e8c9d5dec884ba602183
Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Date: Thu Feb 22 13:52:57 2007 -0800

cpuidle take2: Core cpuidle infrastructure

Announcing 'cpuidle', a new CPU power management infrastructure to manage
idle CPUs in a clean and efficient manner.
cpuidle separates out the drivers that can provide support for multiple types
of idle states and policy governors that decide on what idle state to use
at run time.
A cpuidle driver can support multiple idle states based on parameters like
varying power consumption, wakeup latency, etc (ACPI C-states for example).
A cpuidle governor can be usage model specific (laptop, server,
laptop on battery etc).
Main advantage of the infrastructure being, it allows independent development
of drivers and governors and allows for better CPU power management.

A huge thanks to Adam Belay and Shaohua Li who were part of this mini-project
since its beginning and are greatly responsible for this patchset.

This patch:

Core cpuidle infrastructure.
Introduces a new abstraction layer for cpuidle:
* which manages drivers that can support multiple idles states. Drivers
can be generic or particular to specific hardware/platform
* allows pluging in multiple policy governors that can take idle state policy
decision
* The core also has a set of sysfs interfaces with which administrato can know
about supported drivers and governors and switch them at run time.

Signed-off-by: Adam Belay <abelay@novell.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Signed-off-by: Len Brown <len.brown@intel.com>

drivers/firmware: const-ify DMI API and internals

Three main sets of changes:

1) dmi_get_system_info() return value should have been marked const,
since callers should not be changing that data.

2) const-ify DMI internals, since DMI firmware tables should,
whenever possible, be marked const to ensure we never ever write to
that data area.

3) const-ify DMI API, to enable marking tables const where possible
in low-level drivers.

And if we're really lucky, this might enable some additional
optimizations on the part of the compiler.

The bulk of the changes are #2 and #3, which are interrelated. #1 could
have been a separate patch, but it was so small compared to the others,
it was easier to roll it into this changeset.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

ACPI: disable lower idle C-states across suspend/resume

device_suspend() calls ACPI suspend functions, which seems to have undesired
side effects on lower idle C-states. It took me some time to realize that
especially the VAIO BIOSes (both Andrews jinxed UP and my elfstruck SMP one)
show this effect. I'm quite sure that other bug reports against suspend/resume
about turning the system into a brick have the same root cause.

After fishing in the dark for quite some time, I realized that removing the ACPI
processor module before suspend (this removes the lower C-state functionality)
made the problem disappear. Interestingly enough the propability of having a
bricked box is influenced by various factors (interrupts, size of the ram image,
...). Even adding a bunch of printks in the wrong places made the problem go
away. The previous periodic tick implementation simply pampered over the
problem, which explains why the dyntick / clockevents changes made this more
prominent.

We avoid complex functionality during the boot process and we have to do the
same during suspend/resume. It is a similar scenario and equaly fragile.

Add suspend / resume functions to the ACPI processor code and disable the lower
idle C-states across suspend/resume. Fall back to the default idle
implementation (halt) instead.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sched: sched_clock_idle_[sleep|wakeup]_event()

construct a more or less wall-clock time out of sched_clock(), by
using ACPI-idle's existing knowledge about how much time we spent
idling. This allows the rq clock to work around TSC-stops-in-C2,
TSC-gets-corrupted-in-C3 type of problems.

( Besides the scheduler's statistics this also benefits blktrace and
printk-timestamps as well. )

Furthermore, the precise before-C2/C3-sleep and after-C2/C3-wakeup
callbacks allow the scheduler to get out the most of the period where
the CPU has a reliable TSC. This results in slightly more precise
task statistics.

the ACPI bits were acked by Len.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Len Brown <len.brown@intel.com>

ACPI: fix "Time Problems with 2.6.23-rc1-gf695baf2"

Enable C3 without bm control only for CST based C3.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

[IA64] Convert to generic timekeeping/clocksource

This is a merge of Peter Keilty's initial patch (which was
revived by Bob Picco) for this with Hidetoshi Seto's fixes
and scaling improvements.

Acked-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

ACPI: Enable C3 even when PM2_control is zero

On systems that do not have pm2_control_block, we cannot really use
ARB_DISABLE before C3. We used to disable C3 totally on such systems.

To be compatible with Windows, we need to enable C3 on such systems now.
We just skip ARB_DISABLE step before entering the C3-state and assume
hardware is handling things correctly. Also, ACPI spec is not clear
about pm2_control is _needed_ for C3 or not.

We have atleast one system that need this to enable C3.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: fix 2.6.20 SMP boot regression

Always disable/enable interrupts in the acpi idle routine,
even in the error path.

This is required as the 2.6.20 change in git commit d331e739f5ad2aaa9...
"Fix interrupt race in idle callback" expects the idle handler
to enable interrupt before returning.

There was a case in acpi idle routine, in which interrupt was not being
enabled before return, which caused the system to hang at bootup, while
enabling C-states on an SMP system.

The signature of the hang was that "processor.nocst"
was required to enable boot.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

[PATCH] x86: Log reason why TSC was marked unstable

Change mark_tsc_unstable() so it takes a string argument, which holds the
reason the TSC was marked unstable.

This is then displayed the first time mark_tsc_unstable is called.

This should help us better debug why the TSC was marked unstable on certain
systems and allow us to make sure we're not being overly paranoid when
throwing out this troublesome clocksource.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>

ACPI: remove duplicate include

Thomas's patch for including <asm/apic.h> for x86 UP builds came into
Linus's tree from two different directions, both of which were merged.
This reverts the latter, yanking out the duplicate #include and comment.

Signed-off-by: Ray Lee <ray-lk@madrabbit.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

[PATCH] i386: add command line option "local_apic_timer_c2_ok"

It turned out that it is almost impossible to trust ACPI, BIOS & Co.
regarding the C states. This was the reason to switch the local apic
timer off in C2 state already. OTOH there are sane and well behaving
systems, which get punished by that decision.

Allow the user to confirm that the local apic timer is trustworthy in C2
state. This keeps the default behaviour on the safe side.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Revert "ACPI: Only use IPI on known broken machines (AMD, Dothan/BaniasPentium M)"

This reverts commit 25496caec111481161e7f06bbfa12a533c43cc6f, which
broke bootup on at least Ingo's ThinkPad T60. Need to figure out
exactly what is wrong before we can re-do the logic.

Requested-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ACPI: Only use IPI on known broken machines (AMD, Dothan/BaniasPentium M)

Use IPI for blacklisted CPUs, add parameter IPI vs LAPIC

Currently, Linux disables lapic timer for all machines with C2 and higher
C-state support.

According to Intel only specific Intel models (Banias/Dothan) are broken
in respect of not waking up from C2 with lapic.

However, I am not sure about the naming of the parameter and how it
could/should get integrated into the dyntick part
(CONFIG_GENERIC_CLOCKEVENTS). There, a more fine grained check (TSC
still running?, ..) is needed? Does this make sense (always use
CLOCK_EVT_NOTIFY_BROADCAST_ON, but use OFF if forced by use_ipi=0:
clockevents_notify(use_ipi ? CLOCK_EVT_NOTIFY_BROADCAST_ON :
CLOCK_EVT_NOTIFY_BROADCAST_OFF, &pr->id);

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

[PATCH] clockevents: i386 drivers

Add clockevent drivers for i386: lapic (local) and PIT/HPET (global). Update
the timer IRQ to call into the PIT/HPET driver's event handler and the
lapic-timer IRQ to call into the lapic clockevent driver. The assignement of
timer functionality is delegated to the core framework code and replaces the
compile and runtime evalution in do_timer_interrupt_hook()

Use the clockevents broadcast support and implement the lapic_broadcast
function for ACPI.

No changes to existing functionality.

[ kdump fix from Vivek Goyal <vgoyal@in.ibm.com> ]
[ fixes based on review feedback from Arjan van de Ven <arjan@infradead.org> ]
Cleanups-from: Adrian Bunk <bunk@stusta.de>
Build-fixes-from: Andrew Morton <akpm@osdl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] ACPI keep track of timer broadcasting

This is a preperatory patch for highres/dyntick:

- replace the big #ifdef ARCH_APICTIMER_STOPS_ON_C3 hackery by functions

- remove the double switch in the power verify function (in the worst case
we switched ipi to apic and 20usec later apic to ipi)

- keep track of the the state which stops local APIC timer

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Len Brown <len.brown@intel.com>
Cc: <linux-acpi@vger.kernel.org>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] ACPI: fix missing include for UP

apic.h does not get included on UP compiles. That way the
APICTIMER_STOPS_ON_C3 is not there and UP boxen have no support for timer
broadcasting. This was never noticed, because the lapic timer is only used
for profiling on UP.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ACPI: include apic.h in processor driver for benefit of UP kernels

apic.h does not get included on UP compiles. That way the
APICTIMER_STOPS_ON_C3 is not there and UP boxen have no support for timer
broadcasting. This was never noticed, because the lapic timer is only used
for profiling on UP.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>