Ivy Town idle state table will not be set as intended. Fix it.

Picked up by Coverity - CID 1201420/1201421.

Fixes: 0138d8f0 ("intel_idle: fine-tune IVT residency targets")
Signed-off-by: NChristoph Jaeger <christophjaeger@linux.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Ivy Town processors have slightly different properties
than Ivy Bridge processors, particuarly as socket count grows.
Here we add dedicated tables covering 1-2 socket,
3-4 socket, and > 4 socket IVT configurations.

This reduces the frequency of deep transitions on those systems,
which can impact throughput.
Signed-off-by: NLen Brown <len.brown@intel.com>

Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	register_cpu_notifier(&foobar_cpu_notifier);

	put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	/* Note the use of the double underscored version of the API */
	__register_cpu_notifier(&foobar_cpu_notifier);

	cpu_notifier_register_done();

Fix the intel-idle code by using this latter form of callback registration.

Cc: Len Brown <lenb@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add CPU ID for Atom N2600/N2800 processors. Datasheets indicate support
for this, detailed information about potential quirks or limitations are
missing, though. So we just reuse the definition for the previous ATOM
series. Tests on N2800 systems showed that this addition is fine an can
reduce power consumption by about 0.25 W (personally confirmed on Intel
DN2800MT).
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Bay Trail (BYT) is a family of Silvermont-core Atom Processor SOCs,
including the Intel Atom Processor Z36xxx and Z37xxx Series.

Although it shares the Silvermont core with Avoton,
BYT is optimized for mobile, and thus it supports
different power saving CPU idle states.

Note that not all versions of Bay Trail HW support all
of the states listed in the driver.
Signed-off-by: NLen Brown <len.brown@intel.com>
Tested-by: NAubrey Li <aubrey.li@linux.intel.com>

Like acpi_idle, intel_idle compared sub-state numbers
to the number of supported sub-states -- discarding
sub-states numbers that were numbered >= the number of states.

But some Bay Trail SOCs use sparse sub-state numbers,
so we can't make such a comparison if we are going
to access those states.

So now we simply check that _some_ sub-states are
supported for the given state, and assume that the
sub-state number in our driver is valid.

In practice, the driver is correct, and even if it were not,
the hardware clips invalid sub-state requests to valid ones.

No entries in the driver require this change,
but Bay Trail will need it.
Signed-off-by: NLen Brown <len.brown@intel.com>

intel_idle driver sets dev->state_count to drv->state_count so
the default dev->state_count initialization in cpuidle_enable_device()
(called from cpuidle_register_device()) can be used instead.
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Len Brown <lenb@kernel.org>
Reviewed-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If the system is booted with some CPUs offline C1E promotion disable quirk
won't be applied because on_each_cpu() in intel_idle_cpuidle_driver_init()
operates only on online CPUs. Fix it by adding the C1E promotion disable
handling to intel_idle_cpu_init() (which is also called during CPU_ONLINE
operation).
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Len Brown <lenb@kernel.org>
Reviewed-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Close avn_cstates array with correct marker to avoid overflow
in function intel_idle_cpu_init().

[rjw: The problem was introduced when commit 22e580d0 was merged
 on top of eba682a5 (intel_idle: shrink states tables).]

Fixes: 22e580d0 (intel_idle: Fixed C6 state on Avoton/Rangeley processors)
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This reverts commit 9d046ccb.

Commit 9d046ccb marks all state tables with __initdata, but
the state table may be accessed when doing CPU online, which then
causing system crash as below:

[  204.188841] BUG: unable to handle kernel paging request at ffffffff8227cce8
[  204.196844] IP: [<ffffffff814aa1c0>] intel_idle_cpu_init+0x40/0x130
[  204.203996] PGD 1e11067 PUD 1e12063 PMD 455859063 PTE 800000000227c062
[  204.211638] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[  204.216975] Modules linked in: x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd gpio_ich microcode joydev sb_edac edac_core ipmi_si lpc_ich ipmi_msghandler lp tpm_tis parport wmi mac_hid acpi_pad hid_generic ixgbe isci usbhid dca hid libsas ptp ahci libahci scsi_transport_sas megaraid_sas pps_core mdio
[  204.262815] CPU: 11 PID: 1489 Comm: bash Not tainted 3.13.0-rc7+ #48
[  204.269993] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRIVTIN1.86B.0047.L09.1312061514 12/06/2013
[  204.281646] task: ffff8804303a24a0 ti: ffff880440fac000 task.ti: ffff880440fac000
[  204.290311] RIP: 0010:[<ffffffff814aa1c0>]  [<ffffffff814aa1c0>] intel_idle_cpu_init+0x40/0x130
[  204.300184] RSP: 0018:ffff880440fadd28  EFLAGS: 00010286
[  204.306192] RAX: ffffffff8227cca0 RBX: ffffe8fff1a03400 RCX: 0000000000000007
[  204.314244] RDX: ffff88045f400000 RSI: 0000000000000009 RDI: 0000000000001120
[  204.322296] RBP: ffff880440fadd38 R08: 0000000000000000 R09: 0000000000000001
[  204.330411] R10: 0000000000000001 R11: 0000000000000000 R12: 000000000000001e
[  204.338482] R13: 00000000ffffffdb R14: 0000000000000001 R15: 0000000000000000
[  204.346743] FS:  00007f64f7b0c740(0000) GS:ffff88045ce00000(0000) knlGS:0000000000000000
[  204.355919] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  204.362449] CR2: ffffffff8227cce8 CR3: 0000000444ab0000 CR4: 00000000001407e0
[  204.370520] Stack:
[  204.372853]  000000000000001e ffffffff81f10240 ffff880440fadd50 ffffffff814aa307
[  204.381519]  ffffffff81ea80e0 ffff880440fadda0 ffffffff8185a230 0000000000000000
[  204.390196]  000000000000001e 0000000000000002 0000000000000002 0000000000000000
[  204.398856] Call Trace:
[  204.401683]  [<ffffffff814aa307>] cpu_hotplug_notify+0x57/0x70
[  204.408638]  [<ffffffff8185a230>] notifier_call_chain+0x100/0x150
[  204.415553]  [<ffffffff810a7dae>] __raw_notifier_call_chain+0xe/0x10
[  204.422772]  [<ffffffff81072163>] cpu_notify+0x23/0x50
[  204.428616]  [<ffffffff810723b2>] _cpu_up+0x132/0x1a0
[  204.434361]  [<ffffffff8107249d>] cpu_up+0x7d/0xa0
[  204.439819]  [<ffffffff81836c9c>] cpu_subsys_online+0x3c/0x90
[  204.446345]  [<ffffffff81554625>] device_online+0x45/0xa0
[  204.452471]  [<ffffffff815546ce>] online_store+0x4e/0x80
[  204.458511]  [<ffffffff815519a8>] dev_attr_store+0x18/0x30
[  204.464744]  [<ffffffff812a68f1>] sysfs_write_file+0x151/0x1c0
[  204.471681]  [<ffffffff81217ef1>] vfs_write+0xe1/0x160
[  204.477524]  [<ffffffff8121889c>] SyS_write+0x4c/0x90
[  204.483270]  [<ffffffff8185f2ed>] system_call_fastpath+0x1a/0x1f
[  204.490081] Code: 41 54 41 89 fc 8b 3d 48 25 85 01 53 48 8b 1d 30 25 85 01 48 03 1c c5 40 90 fb 81 48 8b 05 19 25 85 01 c7 43 0c 01 00 00 00 66 90 <48> 83 78 48 00 74 4f 41 83 c0 01 41 39 f0 7e 10 48 c7 c7 38 79
[  204.515723] RIP  [<ffffffff814aa1c0>] intel_idle_cpu_init+0x40/0x130
[  204.522996]  RSP <ffff880440fadd28>
[  204.526976] CR2: ffffffff8227cce8
[  204.530766] ---[ end trace 336f56cc3d1cfc8c ]---

Fixes: 9d046ccb (intel_idle: mark states tables with __initdata tag)
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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

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

Also remove __sti_mwait() as its unused.

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

Linux 3.10 changed the timing of how thread_info->flags is touched:

	x86: Use generic idle loop
	(7d1a9417)

This caused Intel NHM-EX and WSM-EX servers to experience a large number
of immediate MONITOR/MWAIT break wakeups, which caused cpuidle to demote
from deep C-states to shallow C-states, which caused these platforms
to experience a significant increase in idle power.

Note that this issue was already present before the commit above,
however, it wasn't seen often enough to be noticed in power measurements.

Here we extend an errata workaround from the Core2 EX "Dunnington"
to extend to NHM-EX and WSM-EX, to prevent these immediate
returns from MWAIT, reducing idle power on these platforms.

While only acpi_idle ran on Dunnington, intel_idle
may also run on these two newer systems.
As of today, there are no other models that are known
to need this tweak.

Link: http://lkml.kernel.org/r/CAJvTdK=%2BaNN66mYpCGgbHGCHhYQAKx-vB0kJSWjVpsNb_hOAtQ@mail.gmail.comSigned-off-by: NLen Brown <len.brown@intel.com>
Link: http://lkml.kernel.org/r/baff264285f6e585df757d58b17788feabc68918.1387403066.git.len.brown@intel.com
Cc: <stable@vger.kernel.org> # 3.12.x, 3.11.x, 3.10.x
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Corrected the MWAIT flag for C-State C6 on Intel Avoton/Rangeley processors.
Signed-off-by: NArne Bockholdt <linux-kernel@bockholdt.com>
Acked-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Support the "Intel(R) Atom(TM) Processor C2000 Product Family",
formerly code-named Avoton.  It is based on the next generation
Intel Atom processor architecture, formerly code-named Silvermont.
Signed-off-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Small fixup to use CPU_TASKS_FROZEN instead of 0xf.
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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

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

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

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

intel_idle_probe() and intel_idle_cpuidle_driver_init() can be marked
with __init tag as they are only called from intel_idle_init().
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

States tables are only accessed during driver initialization so they
can be marked with __initdata tag.
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no reason to define CPUIDLE_STATE_MAX (currently 10) entries
in states tables if the driver always stops iterating over table when
it encounters first .enter == NULL entry.

$ size drivers/idle/intel_idle.o.*
   text    data     bss     dec     hex filename
   2886    5440      32    8358    20a6 drivers/idle/intel_idle.o.before
   2886    3752      32    6670    1a0e drivers/idle/intel_idle.o.after
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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

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

The start/stop_critical_timings are called from arch/x86/kernel/process.c
in the cpu_idle loop function.

Remove the ones in the cpuidle driver.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NLen Brown <len.brown@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Allow intel_idle and cpuidle to utilize C8, C9, C10
when they are present on...
"Fourth Generation Intel(R) Core(TM) Processors",
which are based on Intel(R) microarchitecture code name Haswell.
Signed-off-by: NLen Brown <len.brown@intel.com>

There is an additional HSW CPU-id, 0x46,
which has C-states exactly like CPU-id 0x45.
Signed-off-by: NLen Brown <len.brown@intel.com>

Here we disable HW promotion of C1 to C1E
and export both C1 and C1E and distinct C-states.

This allows a cpuidle governor to choose a lower latency
C-state than C1E when necessary to satisfy performance
and QOS constraints -- and still save power versus polling.
This also corrects the erroneous latency previously reported
for C1E -- it is 10usec, not 1usec.

Note that if you use "intel_idle.max_cstate=N",
then you must increment N by 1 to get the same behavior
after this change.
Signed-off-by: NLen Brown <len.brown@intel.com>

Remove the assumption that cstate_tables are
indexed by MWAIT flag values.  Each entry
identifies itself via its own flags value.
This change is needed to support multiple states
that share the same MWAIT flags.

Note that this can have an effect on what state is described
by 'N' on cmdline intel_idle.max_cstate=N on some systems.

intel_idle.max_cstate=0 still disables the driver
intel_idle.max_cstate=1 still results in just C1(E)
However, "place holders" in the sparse C-state name-space
(eg. Atom) have been removed.
Signed-off-by: NLen Brown <len.brown@intel.com>

Cosmetic only.

Replace use of MWAIT_MAX_NUM_CSTATES with CPUIDLE_STATE_MAX.
They are both 8, so this patch has no functional change.

The reason to change is that intel_idle will soon be able
to export more than the 8 "major" states supported by MWAIT.
When we hit that limit, it is important to know
where the limit comes from.
Signed-off-by: NLen Brown <len.brown@intel.com>

This patch enables intel_idle to run on the
next-generation Intel(R) Microarchitecture code named "Haswell".
Signed-off-by: NLen Brown <len.brown@intel.com>

The commit, 4202735e
(cpuidle: Split cpuidle_state structure and move per-cpu statistics fields)
observed that the MWAIT flags for Cn on every processor to date were the
same, and created get_driver_data() to supply them.

Unfortunately, that assumption is false, going forward.
So here we restore the MWAIT flags to the cpuidle_state table.
However, instead restoring the old "driver_data" field,
we put the flags into the existing "flags" field,
where they probalby should have lived all along.

This patch does not change any operation.

This patch removes 1 of the 3 users of cpuidle_state_usage.driver_data.
Perhaps some day we'll get rid of the other 2.
Signed-off-by: NLen Brown <len.brown@intel.com>

The 'intel_idle_probe' probes the CPU and sets the CPU notifier.
But if later on during the module initialization we fail (say
in cpuidle_register_driver), we stop loading, but we neglect
to unregister the CPU notifier.  This means that during CPU
hotplug events the system will fail:

calling  intel_idle_init+0x0/0x326 @ 1
intel_idle: MWAIT substates: 0x1120
intel_idle: v0.4 model 0x2A
intel_idle: lapic_timer_reliable_states 0xffffffff
intel_idle: intel_idle yielding to none
initcall intel_idle_init+0x0/0x326 returned -19 after 14 usecs

... some time later, offlining and onlining a CPU:

cpu 3 spinlock event irq 62
BUG: unable to ] __cpuidle_register_device+0x1c/0x120
PGD 99b8b067 PUD 99b95067 PMD 0
Oops: 0000 [#1] SMP
Modules linked in: xen_evtchn nouveau mxm_wmi wmi radeon ttm i915 fbcon tileblit font atl1c bitblit softcursor drm_kms_helper video xen_blkfront xen_netfront fb_sys_fops sysimgblt sysfillrect syscopyarea xenfs xen_privcmd mperf
CPU 0
Pid: 2302, comm: udevd Not tainted 3.8.0-rc3upstream-00249-g09ad159 #1 MSI MS-7680/H61M-P23 (MS-7680)
RIP: e030:[<ffffffff814d956c>]  [<ffffffff814d956c>] __cpuidle_register_device+0x1c/0x120
RSP: e02b:ffff88009dacfcb8  EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff880105380000 RCX: 000000000000001c
RDX: 0000000000000000 RSI: 0000000000000055 RDI: ffff880105380000
RBP: ffff88009dacfce8 R08: ffffffff81a4f048 R09: 0000000000000008
R10: 0000000000000008 R11: 0000000000000000 R12: ffff880105380000
R13: 00000000ffffffdd R14: 0000000000000000 R15: ffffffff81a523d0
FS:  00007f37bd83b7a0(0000) GS:ffff880105200000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 00000000a09ea000 CR4: 0000000000042660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process udevd (pid: 2302, threadinfo ffff88009dace000, task ffff88009afb47f0)
Stack:
 ffffffff8107f2d0 ffffffff810c2fb7 ffff88009dacfce8 00000000ffffffea
 ffff880105380000 00000000ffffffdd ffff88009dacfd08 ffffffff814d9882
 0000000000000003 ffff880105380000 ffff88009dacfd28 ffffffff81340afd
Call Trace:
 [<ffffffff8107f2d0>] ? collect_cpu_info_local+0x30/0x30
 [<ffffffff810c2fb7>] ? __might_sleep+0xe7/0x100
 [<ffffffff814d9882>] cpuidle_register_device+0x32/0x70
 [<ffffffff81340afd>] intel_idle_cpu_init+0xad/0x110
 [<ffffffff81340bc8>] cpu_hotplug_notify+0x68/0x80
 [<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
 [<ffffffff811a1024>] vfs_write+0xb4/0x130
 [<ffffffff811a17ea>] sys_write+0x5a/0xa0
 [<ffffffff816643a9>] system_call_fastpath+0x16/0x1b
Code: 03 18 00 c9 c3 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 48 83 ec 30 48 89 5d e8 4c 89 65 f0 48 89 fb 4c 89 6d f8 e8 84 08 00 00 <48> 8b 78 08 49 89 c4 e8 f8 7f c1 ff 89 c2 b8 ea ff ff ff 84 d2
RIP  [<ffffffff814d956c>] __cpuidle_register_device+0x1c/0x120
 RSP <ffff88009dacfcb8>

This patch fixes that by moving the CPU notifier registration
as the last item to be done by the module.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: 3.6+ <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When debug kernel, the the below information is found:
intel_idle: unaware of model 0x1a MWAIT 4 please contact lenb@kernel.orgACPI: Device input0 -> No ACPI support

so this patch separates it.
Signed-off-by: NYouquan Song <youquan.song@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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

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

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

IVB Xeon currently shares the same parameters IVB client.
Signed-off-by: NLen Brown <len.brown@intel.com>

If the machine is booted without any cpu_idle driver set
(b/c disable_cpuidle() has been called) we should follow
other users of cpu_idle API and check the return value
for NULL before using it.
Reported-and-tested-by: NMark van Dijk <mark@internecto.net>
Suggested-by: NJan Beulich <JBeulich@suse.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

When the system is booted with some cpus offline, the idle
driver is not initialized. When a cpu is set online, the
acpi code call the intel idle init function. Unfortunately
this code introduce a dependency between intel_idle and acpi.

This patch is intended to remove this dependency by using the
notifier of intel_idle. This patch has the benefit of
encapsulating the intel_idle driver and remove some exported
functions.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

From an OS point of view, IVB looks like SNB, but quicker.
Signed-off-by: NLen Brown <len.brown@intel.com>

Fix a code indentation in the function intel_idle_cpu_init that looks
confusing.o
Suggested-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Reviewed-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NMarcos Paulo de Souza <marcos.mage@gmail.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit b66b8b9a ('intel-idle: convert
to x86_cpu_id auto probing') added a distinction between Nehalem and
Westemere processors and changed auto_demotion_disable_flags for the
former to 0.  This was not explained in the commit message, so change
it back.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Acked-by: NThomas Renninger <trenn@suse.de>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit b66b8b9a ('intel-idle: convert
to x86_cpu_id auto probing') put two entries for model 0x2f
(Westmere-EX Xeon) in the device ID table and left out model 0x2e
(Nehalem-EX Xeon).
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Acked-by: NThomas Renninger <trenn@suse.de>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With this it should be automatically loaded on suitable systems by
udev.

The old switch () is replaced with a table based approach, this
also cleans up the code.

Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NThomas Renninger <trenn@suse.de>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Delay the setting up of features (cpuidle, throttling by calling
acpi_processor_start()) to the time when the hotplugged
core got onlined the first time and got fully
initialized.
Signed-off-by: NThomas Renninger <trenn@suse.de>
Signed-off-by: NLen Brown <len.brown@intel.com>