The time spent by a CPU under a given frequency is stored in jiffies unit
in the cpu var cpufreq_stats_table->time_in_state[i], i being the index of
the frequency.

This is what is displayed in the following file on the right column:

     cat /sys/devices/system/cpu/cpuX/cpufreq/stats/time_in_state
     2301000 19835820
     2300000 3172
     [...]

Now cpufreq converts this jiffies unit delta to clock_t before returning it
to the user as in the above file. And that conversion is achieved using the API
cputime64_to_clock_t().

Although it accidentally works on traditional tick based cputime accounting, where
cputime_t maps directly to jiffies, it doesn't work with other types of cputime
accounting such as CONFIG_VIRT_CPU_ACCOUNTING_* where cputime_t can map to nsecs
or any granularity preffered by the architecture.

For example we get a buggy zero delta on full dyntick configurations:

     cat /sys/devices/system/cpu/cpuX/cpufreq/stats/time_in_state
     2301000 0
     2300000 0
     [...]

Fix this with using the proper jiffies_64_t to clock_t conversion.
Reported-and-tested-by: NCarsten Emde <C.Emde@osadl.org>
Signed-off-by: NAndreas Schwab <schwab@linux-m68k.org>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We can't take a big lock around __cpufreq_governor() as this causes
recursive locking for some cases. But calls to this routine must be
serialized for every policy. Otherwise we can see some unpredictable
events.

For example, consider following scenario:

__cpufreq_remove_dev()
 __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
   policy->governor->governor(policy, CPUFREQ_GOV_STOP);
    cpufreq_governor_dbs()
     case CPUFREQ_GOV_STOP:
      mutex_destroy(&cpu_cdbs->timer_mutex)
      cpu_cdbs->cur_policy = NULL;
  <PREEMPT>
store()
 __cpufreq_set_policy()
  __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
    policy->governor->governor(policy, CPUFREQ_GOV_LIMITS);
     case CPUFREQ_GOV_LIMITS:
      mutex_lock(&cpu_cdbs->timer_mutex); <-- Warning (destroyed mutex)
       if (policy->max < cpu_cdbs->cur_policy->cur) <- cur_policy == NULL

And so store() will eventually result in a crash if cur_policy is
NULL at this point.

Introduce an additional variable which would guarantee serialization
here.
Reported-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

__cpufreq_governor() returns with -EBUSY when governor is already
stopped and we try to stop it again, but when it is stopped we must
not allow calls to CPUFREQ_GOV_LIMITS event as well.

This patch adds this check in __cpufreq_governor().
Reported-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Workqueues are preemptible even if works are queued on them with
queue_work_on(). Let's use raw_smp_processor_id() here to silence
the warning.

BUG: using smp_processor_id() in preemptible [00000000] code: kworker/3:2/674
caller is gov_queue_work+0x28/0xb0
CPU: 0 PID: 674 Comm: kworker/3:2 Tainted: G        W    3.10.0 #30
Workqueue: events od_dbs_timer
[<c010c178>] (unwind_backtrace+0x0/0x11c) from [<c0109dec>] (show_stack+0x10/0x14)
[<c0109dec>] (show_stack+0x10/0x14) from [<c03885a4>] (debug_smp_processor_id+0xbc/0xf0)
[<c03885a4>] (debug_smp_processor_id+0xbc/0xf0) from [<c0635864>] (gov_queue_work+0x28/0xb0)
[<c0635864>] (gov_queue_work+0x28/0xb0) from [<c0635618>] (od_dbs_timer+0x108/0x134)
[<c0635618>] (od_dbs_timer+0x108/0x134) from [<c01aa8f8>] (process_one_work+0x25c/0x444)
[<c01aa8f8>] (process_one_work+0x25c/0x444) from [<c01aaf88>] (worker_thread+0x200/0x344)
[<c01aaf88>] (worker_thread+0x200/0x344) from [<c01b03bc>] (kthread+0xa0/0xb0)
[<c01b03bc>] (kthread+0xa0/0xb0) from [<c01061b8>] (ret_from_fork+0x14/0x3c)
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

 - 'Governer' should be 'Governor'.
 - 'S' is used for Siemens (electrical conductance) in SI units,
   so use small 's' for seconds.
Signed-off-by: NStratos Karafotis <stratosk@semaphore.gr>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Function __cpufreq_driver_target() checks if target_freq is within
policy->min and policy->max range. generic_powersave_bias_target() also
checks if target_freq is valid via a cpufreq_frequency_table_target()
call. So, drop the unnecessary duplicate check in *_check_cpu().
Signed-off-by: NStratos Karafotis <stratosk@semaphore.gr>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When a CPU is hot removed we'll cancel all the delayed work items
via gov_cancel_work(). Normally this will just cancels a delayed
timer on each CPU that the policy is managing and the work won't
run, but if the work is already running the workqueue code will
wait for the work to finish before continuing to prevent the
work items from re-queuing themselves like they normally do. This
scheme will work most of the time, except for the case where the
work function determines that it should adjust the delay for all
other CPUs that the policy is managing. If this scenario occurs,
the canceling CPU will cancel its own work but queue up the other
CPUs works to run. For example:

 CPU0                                        CPU1
 ----                                        ----
 cpu_down()
  ...
  __cpufreq_remove_dev()
   cpufreq_governor_dbs()
    case CPUFREQ_GOV_STOP:
     gov_cancel_work(dbs_data, policy);
      cpu0 work is canceled
       timer is canceled
       cpu1 work is canceled                    <work runs>
       <waits for cpu1>                         od_dbs_timer()
                                                 gov_queue_work(*, *, true);
 						  cpu0 work queued
 						  cpu1 work queued
						  cpu2 work queued
						  ...
       cpu1 work is canceled
       cpu2 work is canceled
       ...

At the end of the GOV_STOP case cpu0 still has a work queued to
run although the code is expecting all of the works to be
canceled. __cpufreq_remove_dev() will then proceed to
re-initialize all the other CPUs works except for the CPU that is
going down. The CPUFREQ_GOV_START case in cpufreq_governor_dbs()
will trample over the queued work and debugobjects will spit out
a warning:

WARNING: at lib/debugobjects.c:260 debug_print_object+0x94/0xbc()
ODEBUG: init active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x10
Modules linked in:
CPU: 0 PID: 1491 Comm: sh Tainted: G        W    3.10.0 #19
[<c010c178>] (unwind_backtrace+0x0/0x11c) from [<c0109dec>] (show_stack+0x10/0x14)
[<c0109dec>] (show_stack+0x10/0x14) from [<c01904cc>] (warn_slowpath_common+0x4c/0x6c)
[<c01904cc>] (warn_slowpath_common+0x4c/0x6c) from [<c019056c>] (warn_slowpath_fmt+0x2c/0x3c)
[<c019056c>] (warn_slowpath_fmt+0x2c/0x3c) from [<c0388a7c>] (debug_print_object+0x94/0xbc)
[<c0388a7c>] (debug_print_object+0x94/0xbc) from [<c0388e34>] (__debug_object_init+0x2d0/0x340)
[<c0388e34>] (__debug_object_init+0x2d0/0x340) from [<c019e3b0>] (init_timer_key+0x14/0xb0)
[<c019e3b0>] (init_timer_key+0x14/0xb0) from [<c0635f78>] (cpufreq_governor_dbs+0x3e8/0x5f8)
[<c0635f78>] (cpufreq_governor_dbs+0x3e8/0x5f8) from [<c06325a0>] (__cpufreq_governor+0xdc/0x1a4)
[<c06325a0>] (__cpufreq_governor+0xdc/0x1a4) from [<c0633704>] (__cpufreq_remove_dev.isra.10+0x3b4/0x434)
[<c0633704>] (__cpufreq_remove_dev.isra.10+0x3b4/0x434) from [<c08989f4>] (cpufreq_cpu_callback+0x60/0x80)
[<c08989f4>] (cpufreq_cpu_callback+0x60/0x80) from [<c08a43c0>] (notifier_call_chain+0x38/0x68)
[<c08a43c0>] (notifier_call_chain+0x38/0x68) from [<c01938e0>] (__cpu_notify+0x28/0x40)
[<c01938e0>] (__cpu_notify+0x28/0x40) from [<c0892ad4>] (_cpu_down+0x7c/0x2c0)
[<c0892ad4>] (_cpu_down+0x7c/0x2c0) from [<c0892d3c>] (cpu_down+0x24/0x40)
[<c0892d3c>] (cpu_down+0x24/0x40) from [<c0893ea8>] (store_online+0x2c/0x74)
[<c0893ea8>] (store_online+0x2c/0x74) from [<c04519d8>] (dev_attr_store+0x18/0x24)
[<c04519d8>] (dev_attr_store+0x18/0x24) from [<c02a69d4>] (sysfs_write_file+0x100/0x148)
[<c02a69d4>] (sysfs_write_file+0x100/0x148) from [<c0255c18>] (vfs_write+0xcc/0x174)
[<c0255c18>] (vfs_write+0xcc/0x174) from [<c0255f70>] (SyS_write+0x38/0x64)
[<c0255f70>] (SyS_write+0x38/0x64) from [<c0106120>] (ret_fast_syscall+0x0/0x30)
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

For changing the cpu frequency the i.MX6q has to be switched to some
intermediate clock during the PLL reprogramming. The driver tries
to be clever to keep the enable count correct but gets it wrong. If
the cpufreq is increased it calls clk_disable_unprepare twice
on pll2_pfd2_396m. This puts all other devices which get their clock
from pll2_pfd2_396m into a nonworking state.

Fix this by removing the clk enabling/disabling altogether since the
clk core will do this automatically during a reparent.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The "cpu" and "pclk_p_cclk" was a virtual clock name that was used in
the legacy Tegra clock framework. It was not used after converting to
CCF. Fix it as the correct clock name that we are using.
Tested-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NJoseph Lo <josephl@nvidia.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes DT parsing and uses cpu->of_node instead.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Cc: Jason Cooper <jason@lakedaemon.net>
Acked-by: NAndrew Lunn <andrew@lunn.ch>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Cc: Deepak Sikri <sikrid@qti.qualcomm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Cc: Mark Langsdorf <mark.langsdorf@calxeda.com>
Acked-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

This patch tries to fix lockdep complaint attached below.

It seems that we should always read acquire the cpufreq_rwsem,
whether CONFIG_SMP is enabled or not.  And CONFIG_HOTPLUG_CPU
depends on CONFIG_SMP, so it seems we don't need CONFIG_SMP for the
code enabled by CONFIG_HOTPLUG_CPU.

[    0.504191] =====================================
[    0.504627] [ BUG: bad unlock balance detected! ]
[    0.504627] 3.11.0-rc6-next-20130819 #1 Not tainted
[    0.504627] -------------------------------------
[    0.504627] swapper/1 is trying to release lock (cpufreq_rwsem) at:
[    0.504627] [<ffffffff813d927a>] cpufreq_add_dev+0x13a/0x3e0
[    0.504627] but there are no more locks to release!
[    0.504627]
[    0.504627] other info that might help us debug this:
[    0.504627] 1 lock held by swapper/1:
[    0.504627]  #0:  (subsys mutex#4){+.+.+.}, at: [<ffffffff8134a7bf>] subsys_interface_register+0x4f/0xe0
[    0.504627]
[    0.504627] stack backtrace:
[    0.504627] CPU: 0 PID: 1 Comm: swapper Not tainted 3.11.0-rc6-next-20130819 #1
[    0.504627] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[    0.504627]  ffffffff813d927a ffff88007f847c98 ffffffff814c062b ffff88007f847cc8
[    0.504627]  ffffffff81098bce ffff88007f847cf8 ffffffff81aadc30 ffffffff813d927a
[    0.504627]  00000000ffffffff ffff88007f847d68 ffffffff8109d0be 0000000000000006
[    0.504627] Call Trace:
[    0.504627]  [<ffffffff813d927a>] ? cpufreq_add_dev+0x13a/0x3e0
[    0.504627]  [<ffffffff814c062b>] dump_stack+0x19/0x1b
[    0.504627]  [<ffffffff81098bce>] print_unlock_imbalance_bug+0xfe/0x110
[    0.504627]  [<ffffffff813d927a>] ? cpufreq_add_dev+0x13a/0x3e0
[    0.504627]  [<ffffffff8109d0be>] lock_release_non_nested+0x1ee/0x310
[    0.504627]  [<ffffffff81099d0e>] ? mark_held_locks+0xae/0x120
[    0.504627]  [<ffffffff811510cb>] ? kfree+0xcb/0x1d0
[    0.504627]  [<ffffffff813d77ea>] ? cpufreq_policy_free+0x4a/0x60
[    0.504627]  [<ffffffff813d927a>] ? cpufreq_add_dev+0x13a/0x3e0
[    0.504627]  [<ffffffff8109d2a4>] lock_release+0xc4/0x250
[    0.504627]  [<ffffffff8106c9f3>] up_read+0x23/0x40
[    0.504627]  [<ffffffff813d927a>] cpufreq_add_dev+0x13a/0x3e0
[    0.504627]  [<ffffffff8134a809>] subsys_interface_register+0x99/0xe0
[    0.504627]  [<ffffffff81b19f3b>] ? cpufreq_gov_dbs_init+0x12/0x12
[    0.504627]  [<ffffffff813d7f0d>] cpufreq_register_driver+0x9d/0x1d0
[    0.504627]  [<ffffffff81b19f3b>] ? cpufreq_gov_dbs_init+0x12/0x12
[    0.504627]  [<ffffffff81b1a039>] acpi_cpufreq_init+0xfe/0x1f8
[    0.504627]  [<ffffffff810002ba>] do_one_initcall+0xda/0x180
[    0.504627]  [<ffffffff81ae301e>] kernel_init_freeable+0x12c/0x1bb
[    0.504627]  [<ffffffff81ae2841>] ? do_early_param+0x8c/0x8c
[    0.504627]  [<ffffffff814b4dd0>] ? rest_init+0x140/0x140
[    0.504627]  [<ffffffff814b4dde>] kernel_init+0xe/0xf0
[    0.504627]  [<ffffffff814d029a>] ret_from_fork+0x7a/0xb0
[    0.504627]  [<ffffffff814b4dd0>] ? rest_init+0x140/0x140
Signed-off-by: NLi Zhong <zhong@linux.vnet.ibm.com>
Acked-and-tested-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

To iterate over all policies we currently iterate over all online
CPUs and then get the policy for each of them which is suboptimal.
Use the newly created cpufreq_policy_list for this purpose instead.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq_policy_cpu per-cpu variables are used for storing the ID of
the CPU that manages the given CPU's policy.  However, we also store
a policy pointer for each cpu in cpufreq_cpu_data, so the
cpufreq_policy_cpu information is simply redundant.

It is better to use cpufreq_cpu_data to retrieve a policy and get
policy->cpu from there, so make that happen everywhere and drop the
cpufreq_policy_cpu per-cpu variables which aren't necessary any more.

[rjw: Changelog]
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We don't need to check if event is CPUFREQ_GOV_POLICY_INIT and put
governor module as we are sure event can only be START/STOP here.

Remove the useless check.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq_policy_list is a list of active policies.  We do remove
policies from this list when all CPUs belonging to that policy are
removed.  But during system suspend we don't really free a policy
struct as it will be used again during resume, so we didn't remove
it from cpufreq_policy_list as well..

However, this is incorrect.  We are saying this policy isn't valid
anymore and must not be referenced (though we haven't freed it), but
it can still be used by code that iterates over cpufreq_policy_list.

Remove policy from this list during system suspend as well.
Of course, we must add it back whenever the first CPU belonging to
that policy shows up.

[rjw: Changelog]
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Align closing brace '}' of an if block.

[rjw: Subject and changelog]
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Revert commit eb608521 (cpufreq: Use cpufreq_policy_list for iterating
over policies), because it breaks system suspend/resume on multiple
machines.

It either causes resume to block indefinitely or causes the BUG_ON()
in lock_policy_rwsem_##mode() to trigger on sysfs accesses to cpufreq
attributes.

Conflicts:
	drivers/cpufreq/cpufreq.c

This local symbol is used only in this file.
Fix the following sparse warnings:

drivers/cpufreq/unicore2-cpufreq.c:27:5: warning: symbol 'ucv2_verify_speed' was not declared. Should it be static?
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

__init belongs after the return type on functions, not before it.
Signed-off-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

__init belongs after the return type on functions, not before it.
Signed-off-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

__init belongs after the return type on functions, not before it.
Signed-off-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Replace ARRAY_AND_SIZE(e) in function argument position to avoid
hiding the arity of the called function.

The semantic match that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression e,f;
@@

f(...,
- ARRAY_AND_SIZE(e)
+ e,ARRAY_SIZE(e)
  ,...)
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since NULL could in theory be a valid regulator we ought to check for
IS_ERR() rather than for NULL. In practice this is unlikely to be an
issue but it's better for neatness.
Signed-off-by: NMark Brown <broonie@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Standardise the defintion of the cpb (Core Performance Boost)
attribute in the acpi-cpufreq driver via the cpufreq_freq_attr_rw
macro.

[rjw: Subject and changelog]
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

* remove superfluous pr_debug() call from exynos_cpufreq_init()
  (init errors are always logged anyway)
* add dummy per-SoC type init functions to exynos-cpufreq.h
* make per-SoC type cpufreq config options selectable
* make CONFIG_ARM_EXYNOS_CPUFREQ config option invisible to user and
  automatically enable it when needed

This patch fixes following issues:
* EXYNOS per-SoC type cpufreq support (i.e. exynos4210-cpufreq.c) being
  always built if given SoC support was enabled (i.e. CPU_EXYNOS4210),
  even if common EXYNOS cpufreq support was disabled
* inability to select cpufreq for each SoC type separately (it could
  be only enabled/disabled for all SoCs for which support was enabled)
* EXYNOS5440 cpufreq support was always enabled when EXYNOS5440
  support was enabled and couldn't be disabled
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: NTomasz Figa <t.figa@samsung.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

This patch fixes the issue of un-necessary setting the clock controller
when the new target frequency is same as the current one. This case usually
occurs with governors like ondemand which passes the target frequency as the
percentage of average frequency. This check is present in most of the cpufreq
drivers.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NAmit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>

The __cpufreq_governor() function can fail in rare cases especially
if there are bugs in cpufreq drivers.  Thus we must stop processing
as soon as this routine fails, otherwise it may result in undefined
behavior.

This patch adds error checking code whenever this routine is called
from any place.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We don't need to set .owner = THIS_MODULE any more in cpufreq drivers
as this field isn't used any more by the cpufreq core.

This patch removes it and updates all dependent drivers accordingly.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Critical sections of the cpufreq core are protected with the help of
the driver module owner's refcount, which isn't the correct approach,
because it causes rmmod to return an error when some routine has
updated that refcount.

Let's use rwsem for this purpose instead.  Only
cpufreq_unregister_driver() will use write sem
and everybody else will use read sem.

[rjw: Subject & changelog]
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The cpufreq governor owner refcount usage is broken.  We should only
increment that refcount when a CPUFREQ_GOV_POLICY_INIT event has come
and it should only be decremented if CPUFREQ_GOV_POLICY_EXIT has come.

Currently, there can be situations where the governor is in use, but
we have allowed it to be unloaded which may result in undefined
behavior.  Let's fix it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

To iterate over all policies we currently iterate over all CPUs and
then get the policy for each of them.  Let's use the newly created
cpufreq_policy_list for this purpose.

[rjw: Changelog]
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Policies available in the cpufreq framework are now linked together.
They are accessible via cpufreq_policy_list defined in the cpufreq
core.

[rjw: Fix from Yinghai Lu folded in]
Signed-off-by: NLukasz Majewski <l.majewski@samsung.com>
Signed-off-by: NMyungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>