CPUFREQ_UPDATE_POLICY_CPU notifications were used only from cpufreq-stats which
doesn't use it anymore. Remove them.

This also decrements values of other notification macros defined after
CPUFREQ_UPDATE_POLICY_CPU by 1 to remove gaps. Hopefully all users are using
macro's instead of direct numbers and so they wouldn't break as macro values are
changed now.
Reviewed-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

'cpu' field of struct cpufreq_stats isn't used anymore and so can be dropped.
This change makes cpufreq_stats_update_policy_cpu() empty and so that is removed
as well.
Reviewed-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

'last_cpu' was used only from cpufreq-stats and isn't used anymore. Get rid of
it.
Reviewed-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently we name objects of 'struct cpufreq_stats' as 'stat' and 'stats'.
Use 'stats' to make it consistent.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

All CPUs sharing a cpufreq policy share stats too. For this reason,
add a stats pointer to struct cpufreq_policy and drop per-CPU variable
cpufreq_stats_table used for accessing cpufreq stats so as to reduce
code complexity.
Reviewed-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It is better to pass a struct cpufreq_stats pointer to cpufreq_stats_update()
instead of a CPU number, because that's all it needs.

Even if we pass a cpu number to cpufreq_stats_update(), it reads the per-cpu
variable to get 'stats' out of it. So we are doing these operations
unnecessarily:
- First getting the cpu number to pass to cpufreq_stats_update(), stat->cpu.
- And then getting stats from the cpu, per_cpu(cpufreq_stats_table, cpu).
Reviewed-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

While we allocate stats, we do need to check if freq-table is present
or not as we need to use it then. But while freeing stats, all we need
to know is if stats holds a valid pointer value. There is no use of
testing if cpufreq table is present or not.

Don't check it.
Reviewed-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

'cur_time' is defined in the first line and is then assigned a value
in the next line. Initialize it while defining it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It was never used, but is there since the first commit. Remove it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

__cpufreq_stats_create_table() is called from:

- cpufreq notifier on creation of a new policy. Stats will always be
  NULL here.
- cpufreq_stats_init() for all CPUs as cpufreq-stats might have been
  initialized after cpufreq driver. For any policy, 'stats' will be
  NULL for the first CPU only and will be valid for all other CPUs
  managed by the same policy.

While we return for other CPUs, we don't return the right error value.
It's not that we would fail with -EBUSY. But generally, this is what
these return values mean:
- EBUSY: we are busy right now, try again. And the retry attempt might
  be immediate.
- EEXIST: We already have what you are trying to create and there is no
  need to create it again, and so no more tries are required.
Reviewed-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The MODULE_DESCRIPTION() string is just too long and then is broken into
multiple lines just to make checkpatch happy.

Rewrite it to make it more precise.
Reviewed-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We need to initialize completion and work only on policy allocation and not
really on the policy restore side and so we better move this piece of code to
cpufreq_policy_alloc().
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

CPUFREQ_STICKY flag is set by drivers which don't want to get unregistered
even if cpufreq-core isn't able to initialize policy for any CPU.

When this flag isn't set, we try to unregister the driver. To find out
which CPUs are registered and which are not, we try to check per_cpu
cpufreq_cpu_data for all CPUs. Because we have a list of valid policies
available now, we better check if the list is empty or not instead of
the 'for' loop. That will be much more efficient.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

These variables are just used within adjust_jiffies() and so must be
local to it. Also there is no need of a dummy routine for CONFIG_SMP
case as we can take care of all that with help of macros in the same
routine. It doesn't look that ugly.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We just need to check if a 'policy' is already present for the cpu we are
adding. We don't need to take all the locks and do kobject usage updates. Use
the light-weight cpufreq_cpu_get_raw() routine instead.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no need of this separate variable, use 'policy' instead.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

These are messing up more than the benefit they provide. It isn't
a lot of code anyway, that we will compile without them.

Kill them.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We should first check if a cpufreq driver is already registered or not
before updating driver_data->flags.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no point finding out the 'policy' again within __cpufreq_get()
when all the callers already have it. Just make them pass policy instead.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is no point finding out the 'policy' again within cpufreq_out_of_sync()
when all the callers already have it. Just make them pass policy instead.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Either we can be setpolicy or target type, nothing else. And so the
else part of setpolicy will automatically be of has_target() type.
And so we don't need to check it again.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Remove unnecessary from find_governor's name.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are two 'if' blocks here, checking for !cpufreq_driver->setpolicy and
has_target(). Both are actually doing the same thing, merge them.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

No need of an unnecessary line break.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We can live without it and so we should.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It doesn't make any sense at all and is a leftover of some earlier commit.
Remove it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We should stop cpufreq governors when we shut down the system.  If we
don't do this, we can end up with this deadlock:

1. cpufreq governor may be running on a CPU other than CPU0.
2. In machine_restart() we call smp_send_stop() which stops CPUs.
   If one of these CPUs was actively running a cpufreq governor
   then it may have the mutex / spinlock needed to access the main
   PMIC in the system (perhaps over I2C)
3. If a machine needs access to the main PMIC in order to shutdown
   then it will never get it since the mutex was lost when the other
   CPU stopped.
4. We'll hang (possibly eventually hitting the hard lockup detector).

Let's avoid the problem by stopping the cpufreq governor at shutdown,
which is a sensible thing to do anyway.
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This platform_driver does not need to set an owner, it will be
populated by the driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If ACPI _PPC changed notification happens before governor was initiated
while kernel is booting, a NULL pointer dereference will be triggered:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
 IP: [<ffffffff81470453>] __cpufreq_governor+0x23/0x1e0
 PGD 0
 Oops: 0000 [#1] SMP
 ... ...
 RIP: 0010:[<ffffffff81470453>]  [<ffffffff81470453>]
 __cpufreq_governor+0x23/0x1e0
 RSP: 0018:ffff881fcfbcfbb8  EFLAGS: 00010286
 RAX: 0000000000000000 RBX: ffff881fd11b3980 RCX: ffff88407fc20000
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff881fd11b3980
 RBP: ffff881fcfbcfbd8 R08: 0000000000000000 R09: 000000000000000f
 R10: ffffffff818068d0 R11: 0000000000000043 R12: 0000000000000004
 R13: 0000000000000000 R14: ffffffff8196cae0 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff881fffc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000030 CR3: 00000000018ae000 CR4: 00000000000407f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process kworker/0:3 (pid: 750, threadinfo ffff881fcfbce000, task
 ffff881fcf556400)
 Stack:
  ffff881fffc17d00 ffff881fcfbcfc18 ffff881fd11b3980 0000000000000000
  ffff881fcfbcfc08 ffffffff81470d08 ffff881fd11b3980 0000000000000007
  ffff881fcfbcfc18 ffff881fffc17d00 ffff881fcfbcfd28 ffffffff81472e9a
 Call Trace:
  [<ffffffff81470d08>] __cpufreq_set_policy+0x1b8/0x2e0
  [<ffffffff81472e9a>] cpufreq_update_policy+0xca/0x150
  [<ffffffff81472f20>] ? cpufreq_update_policy+0x150/0x150
  [<ffffffff81324a96>] acpi_processor_ppc_has_changed+0x71/0x7b
  [<ffffffff81320bcd>] acpi_processor_notify+0x55/0x115
  [<ffffffff812f9c29>] acpi_device_notify+0x19/0x1b
  [<ffffffff813084ca>] acpi_ev_notify_dispatch+0x41/0x5f
  [<ffffffff812f64a4>] acpi_os_execute_deferred+0x27/0x34

The root cause is a race conditon -- cpufreq core and acpi-cpufreq driver
were initiated, but cpufreq_governor wasn't and _PPC changed notification
happened, __cpufreq_governor() was called within acpi_os_execute_deferred
kernel thread context.

To fix this panic issue, add pointer checking code in __cpufreq_governor()
before pointer policy->governor is to be dereferenced.
Signed-off-by: NEthan Zhao <ethan.zhao@oracle.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

I'm leaving Red Hat at the end of December 2014, so remove all
references to my soon-to-be-dead address.

(There are some references left in the tree, that need additional
changes, I'll send those through the AGP maintainers).
Signed-off-by: NDave Jones <davej@codemonkey.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

cpufreq-dt driver supports mode when OPP table is provided by platform
code and not device tree. However on certain platforms code that fills
OPP table may run after cpufreq driver tries to initialize, so let's
report -EPROBE_DEFER if we do not find any entires in OPP table for the
CPU.
Signed-off-by: NDmitry Torokhov <dtor@chromium.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add a few comments in the code which calculates busyness to
clarify parts of the algorithm.
Signed-off-by: NKristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

To force loading on Oracle Sun X86 servers, provide one kernel command line
parameter

  intel_pstate = force

For those who are aware of the risk of no power capping capabily working
and try to get better performance with this driver.
Signed-off-by: NEthan Zhao <ethan.zhao@oracle.com>
Tested-by: NAlexey Kodanev <alexey.kodanev@oracle.com>
Reviewed-by: NLinda Knippers <linda.knippers@hp.com>
Acked-by: NKristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Oracle Sun X86 servers have dynamic power capping capability that works via
ACPI _PPC method etc, so skip loading this driver if Sun server has ACPI _PPC
enabled.
Signed-off-by: NEthan Zhao <ethan.zhao@oracle.com>
Tested-by: NLinda Knippers <linda.knippers@hp.com>
Acked-by: NKristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OPP layer now supports freeing of OPPs and we should free them once they aren't
useful anymore.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OPP layer now supports freeing of OPPs and we should free them once they aren't
useful anymore.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OPP layer now supports freeing of OPPs and we should free them once they aren't
useful anymore.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

OPP layer now supports freeing of OPPs and we should free them once they aren't
useful anymore.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently we are calling of_cpufreq_cooling_register() from ->init() callback.
At this point of time cpufreq driver's policy isn't completely ready to be used
as few of its fields/structure/pointers aren't yet initialized.

Because of_cpufreq_cooling_register() tries to access policy with help of
cpufreq_cpu_get() and then tries to get freq-table as well, these calls fail.

To fix this, register the cooling device after the policy is ready to be used.
And the right callback for it is the newly added ->ready() one.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NEduardo Valentin <edubezval@gmail.com>
Tested-by: NEduardo Valentin <edubezval@gmail.com>
Reviewed-by: NLukasz Majewski <l.majewski@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently there is no callback for cpufreq drivers which is called once the
policy is ready to be used. There are some requirements where such a callback is
required.

One of them is registering a cooling device with the help of
of_cpufreq_cooling_register(). This routine tries to get 'struct cpufreq_policy'
for CPUs which isn't yet initialed at the time ->init() is called and so we face
issues while registering the cooling device.

Because we can't register cooling device from ->init(), we need a callback that
is called after the policy is ready to be used and hence we introduce ->ready()
callback.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NEduardo Valentin <edubezval@gmail.com>
Tested-by: NEduardo Valentin <edubezval@gmail.com>
Reviewed-by: NLukasz Majewski <l.majewski@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>