The architectures that override cputime_t (s390, ppc) don't provide
any version of nsecs_to_cputime(). Indeed this cputime_t implementation
by backend only happens when CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y under
which the core code doesn't make any use of nsecs_to_cputime().

At least for now.

We are going to make a broader use of it so lets provide a default
version with a per usecs granularity. It should be good enough for most
usecases.

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

When cpufreq_stats is compiled in as a module, cpufreq driver would
have already been registered. And so the CPUFREQ_CREATE_POLICY
notifiers wouldn't be called for it. Hence no sysfs entries for stats. :(

This patch calls cpufreq_stats_create_table() for each online CPU from
cpufreq_stats_init() and so if policy is already created for CPUx then
we will register sysfs stats for it.

When its not compiled as module, we will return early as policy wouldn't
be found for any of the CPUs.
Acked-by: NNicolas Pitre <nico@linaro.org>
Tested-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We don't have code paths now where we need to do these two things
separately, so it is better do them in a single routine. Just as
they are allocated in a single routine.
Acked-by: NNicolas Pitre <nico@linaro.org>
Tested-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Either CPUs are hot-unplugged or suspend/resume occurs, cpufreq core
will send notifications to cpufreq-stats and stats structure and sysfs
entries would be correctly handled..

And so we don't actually need hotcpu notifiers in cpufreq-stats anymore.
We were only handling cpu hot-unplug events here and that are already
taken care of by POLICY notifiers.
Acked-by: NNicolas Pitre <nico@linaro.org>
Tested-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are several problems with cpufreq stats in the way it handles
cpufreq_unregister_driver() and suspend/resume..

 - We must not lose data collected so far when suspend/resume happens
   and so stats directories must not be removed/allocated during these
   operations, which is done currently.

 - cpufreq_stat has registered notifiers with both cpufreq and hotplug.
   It adds sysfs stats directory with a cpufreq notifier: CPUFREQ_NOTIFY
   and removes this directory with a notifier from hotplug core.

   In case cpufreq_unregister_driver() is called (on rmmod cpufreq driver),
   stats directories per cpu aren't removed as CPUs are still online. The
   only call cpufreq_stats gets is cpufreq_stats_update_policy_cpu() for
   all CPUs except the last of each policy. And pointer to stat information
   is stored in the entry for last CPU in the per-cpu cpufreq_stats_table.
   But policy structure would be freed inside cpufreq core and so that will
   result in memory leak inside cpufreq stats (as we are never freeing
   memory for stats).

   Now if we again insert the module cpufreq_register_driver() will be
   called and we will again allocate stats data and put it on for first
   CPU of every policy.  In case we only have a single CPU per policy, we
   will return with a error from cpufreq_stats_create_table() due to this
   code:

	if (per_cpu(cpufreq_stats_table, cpu))
		return -EBUSY;

   And so probably cpufreq stats directory would not show up anymore (as
   it was added inside last policies->kobj which doesn't exist anymore).
   I haven't tested it, though. Also the values in stats files wouldn't
   be refreshed as we are using the earlier stats structure.

 - CPUFREQ_NOTIFY is called from cpufreq_set_policy() which is called for
   scenarios where we don't really want cpufreq_stat_notifier_policy() to get
   called. For example whenever we are changing anything related to a policy:
   min/max/current freq, etc. cpufreq_set_policy() is called and so cpufreq
   stats is notified. Where we don't do any useful stuff other than simply
   returning with -EBUSY from cpufreq_stats_create_table(). And so this
   isn't the right notifier that cpufreq stats..

 Due to all above reasons this patch does following changes:
 - Add new notifiers CPUFREQ_CREATE_POLICY and CPUFREQ_REMOVE_POLICY,
   which are only called when policy is created/destroyed. They aren't
   called for suspend/resume paths..
 - Use these notifiers in cpufreq_stat_notifier_policy() to create/destory
   stats sysfs entries. And so cpufreq_unregister_driver() or suspend/resume
   shouldn't be a problem for cpufreq_stats.
 - Return early from cpufreq_stat_cpu_callback() for suspend/resume sequence,
   so that we don't free stats structure.
Acked-by: NNicolas Pitre <nico@linaro.org>
Tested-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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>

Chapter 14 of Documentation/CodingStyle says:

The preferred form for passing a size of a struct is the following:

	p = kmalloc(sizeof(*p), ...);

The alternative form where struct name is spelled out hurts
readability and introduces an opportunity for a bug when the pointer
variable type is changed but the corresponding sizeof that is passed
to a memory allocator is not.

This wasn't followed consistently in drivers/cpufreq, let's make it
more consistent by always following this rule.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

They are called policy, cur_policy, new_policy, data, etc.  Just call
them policy wherever possible.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch addresses the following issues in the header files in the
cpufreq core:
 - Include headers in ascending order, so that we don't add same
   many times by mistake.
 - <asm/> must be included after <linux/>, so that they override
   whatever they need to.
 - Remove unnecessary includes.
 - Don't include files already included by cpufreq.h or
   cpufreq_governor.h.

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

Now that we have the infrastructure to perform a light-weight init/tear-down,
use that in the cpufreq CPU hotplug notifier when invoked from the
suspend/resume path.

This also ensures that the file permissions of the cpufreq sysfs files are
preserved across suspend/resume, something which commit a66b2e (cpufreq:
Preserve sysfs files across suspend/resume) originally intended to do, but
had to be reverted due to other problems.
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The call to cpufreq_update_policy() is placed in the CPU hotplug callback
of cpufreq_stats, which has a higher priority than the CPU hotplug callback
of cpufreq-core. As a result, during CPU_ONLINE/CPU_ONLINE_FROZEN, we end up
calling cpufreq_update_policy() *before* calling cpufreq_add_dev() !
And for uninitialized CPUs, it just returns silently, not doing anything.

To add to that, cpufreq_stats is not even the right place to call
cpufreq_update_policy() to begin with. The cpufreq core ought to handle
this in its own callback, from an elegance/relevance perspective.

So move the invocation of cpufreq_update_policy() to cpufreq_cpu_callback,
and place it *after* cpufreq_add_dev().
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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 5e427ec2 ("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/cpufreq uses of the __cpuinit macros
from all C files.

[1] https://lkml.org/lkml/2013/5/20/589

[v2: leave 2nd lines of args misaligned as requested by Viresh]
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: cpufreq@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Acked-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

commit a66b2e (cpufreq: Preserve sysfs files across suspend/resume)
has unfortunately caused several things in the cpufreq subsystem to
break subtly after a suspend/resume cycle.

The intention of that patch was to retain the file permissions of the
cpufreq related sysfs files across suspend/resume.  To achieve that,
the commit completely removed the calls to cpufreq_add_dev() and
__cpufreq_remove_dev() during suspend/resume transitions.  But the
problem is that those functions do 2 kinds of things:
  1. Low-level initialization/tear-down that are critical to the
     correct functioning of cpufreq-core.
  2. Kobject and sysfs related initialization/teardown.

Ideally we should have reorganized the code to cleanly separate these
two responsibilities, and skipped only the sysfs related parts during
suspend/resume.  Since we skipped the entire callbacks instead (which
also included some CPU and cpufreq-specific critical components),
cpufreq subsystem started behaving erratically after suspend/resume.

So revert the commit to fix the regression.  We'll revisit and address
the original goal of that commit separately, since it involves quite a
bit of careful code reorganization and appears to be non-trivial.

(While reverting the commit, note that another commit f51e1eb6
 (cpufreq: Fix cpufreq regression after suspend/resume) already
 reverted part of the original set of changes.  So revert only the
 remaining ones).
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NPaul Bolle <pebolle@tiscali.nl>
Cc: 3.10+ <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Toralf Förster reported that the cpufreq ondemand governor behaves erratically
(doesn't scale well) after a suspend/resume cycle. The problem was that the
cpufreq subsystem's idea of the cpu frequencies differed from the actual
frequencies set in the hardware after a suspend/resume cycle. Toralf bisected
the problem to commit a66b2e50 (cpufreq: Preserve sysfs files across
suspend/resume).

Among other (harmless) things, that commit skipped the call to
cpufreq_update_policy() in the resume path. But cpufreq_update_policy() plays
an important role during resume, because it is responsible for checking if
the BIOS changed the cpu frequencies behind our back and resynchronize the
cpufreq subsystem's knowledge of the cpu frequencies, and update them
accordingly.

So, restore the call to cpufreq_update_policy() in the resume path to fix
the cpufreq regression.
Reported-and-tested-by: NToralf Förster <toralf.foerster@gmx.de>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: 3.10+ <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There were a few noticeable formatting issues in core cpufreq code.
This cleans them up to make code look better.  The changes include:
 - Whitespace cleanup.
 - Rearrangements of code.
 - Multiline comments fixes.
 - Formatting changes to fit 80 columns.

Copyright information in cpufreq.c is also updated to include my name
for 2013.

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

The file permissions of cpufreq per-cpu sysfs files are not preserved
across suspend/resume because we internally go through the CPU
Hotplug path which reinitializes the file permissions on CPU online.

But the user is not supposed to know that we are using CPU hotplug
internally within suspend/resume (IOW, the kernel should not silently
wreck the user-set file permissions across a suspend cycle).
Therefore, we need to preserve the file permissions as they are
across suspend/resume.

The simplest way to achieve that is to just not touch the sysfs files
at all - ie., just ignore the CPU hotplug notifications in the
suspend/resume path (_FROZEN) in the cpufreq hotplug callback.
Reported-by: NRobert Jarzmik <robert.jarzmik@intel.com>
Reported-by: NDurgadoss R <durgadoss.r@intel.com>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In cpufreq_stats_free_sysfs() we aren't balancing calls to
cpufreq_cpu_get() with cpufreq_cpu_put(). This will never let us have
ref count to policy->kobj as zero.

We will get a hang if somehow cpufreq_driver_unregister() is called.
And that can happen when we compile our driver as module and
insmod/rmmod it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NAmit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The sysfs files for cpufreq_stats are created in cpufreq_stats_create_table()
called from cpufreq_stat_notifier_policy() when a policy is added to
the cpu. cpufreq_stats_create_table() will not be called if the
scaling driver does not export a frequency table to cpufreq.  Use the
same fence on tear down.
Signed-off-by: NDirk Brandewie <dirk.j.brandewie@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Macro "CPUFREQ_STATDEVICE_ATTR" is defined local to cpufreq_stats.c file and is
almost a copy of the generic version present in cpufreq.h file. Lets use the
generic version instead.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Implement a generic helper function policy_is_shared() to replace the
current dbs_sw_coordinated_cpus() at cpufreq level, so that it can be
used by code other than cpufreq governors.
Suggested-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NFabio Baltieri <fabio.baltieri@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

__cpufreq_remove_dev() is called on multiple occasions: cpufreq_driver
unregister and cpu removals.

Current implementation of this routine is overly complex without much need. If
the cpu to be removed is the policy->cpu, we remove the policy first and add all
other cpus again from policy->cpus and then finally call __cpufreq_remove_dev()
again to remove the cpu to be deleted. Haahhhh..

There exist a simple solution to removal of a cpu:
- Simply use the old policy structure
- update its fields like: policy->cpu, etc.
- notify any users of cpufreq, which depend on changing policy->cpu

Hence this patch, which tries to implement the above theory. It is tested well
by myself on ARM big.LITTLE TC2 SoC, which has 5 cores (2 A15 and 3 A7). Both
A15's share same struct policy and all A7's share same policy structure.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch forces complete struct cpufreq_stats allocation for all cpus before
registering CPUFREQ_TRANSITION_NOTIFIER notifier, otherwise in some conditions
cpufreq_stat_notifier_trans() can be called in the middle of stats allocation,
in this case cpufreq_stats_table already exists, but stat->freq_table is NULL.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There were few sparse warnings due to mismatch of type on function arguments.
Two types were used u64 and cputime64_t. Both are actually u64, so use u64 only.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When system enters sleep, non-boot CPUs will be disabled.
Cpufreq stats sysfs is created when the CPU is up, but it is not
freed when the CPU is going down. This will cause memory leak.
Signed-off-by: Nxiaobing tu <xiaobing.tu@intel.com>
Signed-off-by: Nguifang tang <guifang.tang@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem
and converts the devices to regular devices. The sysdev drivers are
implemented as subsystem interfaces now.

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Userspace relies on events and generic sysfs subsystem infrastructure
from sysdev devices, which are made available with this conversion.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make cputime_t and cputime64_t nocast to enable sparse checking to
detect incorrect use of cputime. Drop the cputime macros for simple
scalar operations. The conversion macros are still needed.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

So that we can clean up the header files and not be relying
on implicit includes from device.h ---> module.h
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

If the driver submitted an non-existing pol>cur value (say it
used the default initialized value of zero), when the cpufreq
stats tries to setup its initial values it incorrectly sets
stat->last_index to -1 (or 0xfffff...). And cpufreq_stats_update
tries to update at that index location and fails.

This can be caused by:

stat->last_index = freq_table_get_index(stat, policy->cur);

not finding the appropiate frequency in the table (b/c the policy->cur
is wrong) and we end up crashing. The fix however is
concentrated in the 'cpufreq_stats_update' as the last_index
(and old_index) are updated there. Which means it can reset
the last_index to -1 again and on the next iteration cause a crash.

Without this patch, the following crash is observed:

powernow-k8: Found 1 AMD Athlon(tm) 64 Processor 3700+ (1 cpu cores) (version 2.20.00)
powernow-k8: fid 0x2 (1000 MHz), vid 0x12
powernow-k8: fid 0xa (1800 MHz), vid 0xa
powernow-k8: fid 0xc (2000 MHz), vid 0x8
powernow-k8: fid 0xe (2200 MHz), vid 0x8
Marking TSC unstable due to cpufreq changes
powernow-k8: fid trans failed, fid 0x2, curr 0x0
BUG: unable to handle kernel paging request at ffff880807e07b78
IP: [<ffffffff81479163>] cpufreq_stats_update+0x46/0x5b
.. snip..
Pid: 1, comm: swapper Not tainted 3.0.0-rc2 #45 MICRO-STAR INTERNATIONAL CO., LTD MS-7094/MS-7094
..snip..
Call Trace:
 [<ffffffff81479248>] cpufreq_stat_notifier_trans+0x48/0x7c
 [<ffffffff81095d68>] notifier_call_chain+0x32/0x5e
 [<ffffffff81095e6b>] __srcu_notifier_call_chain+0x47/0x63
 [<ffffffff81095e96>] srcu_notifier_call_chain+0xf/0x11
 [<ffffffff81477e7a>] cpufreq_notify_transition+0x111/0x134
 [<ffffffff8147b0d4>] powernowk8_target+0x53b/0x617
 [<ffffffff8147723a>] __cpufreq_driver_target+0x2e/0x30
 [<ffffffff8147a127>] cpufreq_governor_dbs+0x339/0x356
 [<ffffffff81477394>] __cpufreq_governor+0xa8/0xe9
 [<ffffffff81477525>] __cpufreq_set_policy+0x132/0x13e
 [<ffffffff8147848d>] cpufreq_add_dev_interface+0x272/0x28c
Reported-by: NTobias Diedrich <ranma+xen@tdiedrich.de>
Tested-by: NTobias Diedrich <ranma+xen@tdiedrich.de>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NDave Jones <davej@redhat.com>

cpufreq_stats leaves behind its sysfs entries, which causes a panic
when something stumbled across them.
(Discovered by unloading cpufreq_stats while powertop was loaded).
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: stable@kernel.org

Fixed brace coding style issue.
Signed-off-by: NKarthigan Srinivasan <karthigan.srinivasan@hp.com>
Signed-off-by: NDave Jones <davej@redhat.com>

When a CPU is taken offline in an SMP system, cpufreq_remove_dev()
nulls out the per-cpu policy before cpufreq_stats_free_table() can
make use of it.  cpufreq_stats_free_table() then skips the
call to sysfs_remove_group(), leaving about 100 bytes of sysfs-related
memory unclaimed each time a CPU-removal occurs. Break up
cpu_stats_free_table into sysfs and table portions, and
call the sysfs portion early.
Signed-off-by: NSteven Finney <steven.finney@palm.com>
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: stable@kernel.org

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

Signed-off-by: NDave Jones <davej@redhat.com>

Change cpufreq_policy and cpufreq_governor pointer tables
from arrays to per_cpu variables in the cpufreq subsystem.

Also some minor complaints from checkpatch.pl fixed.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.gitSigned-off-by: NMike Travis <travis@sgi.com>
Signed-off-by: NDave Jones <davej@redhat.com>

Sometimes old_index != stat->last_index, see cpufreq_update_policy, bios can
change cpu setting in resume.  In my test, after resume cpu is in lowest
speed, but the stat info shows cpu is in full speed.  This patch makes the
stat info correct after a resume.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Jones <davej@redhat.com>

Fix show_trans_table when it overflows PAGE_SIZE.

* Not all snprintf calls were protected against being passed a negative
length.
* When show_trans_table overflows, len might be > PAGE_SIZE. In that case,
returns PAGE_SIZE.
Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net>
Signed-off-by: NDave Jones <davej@codemonkey.org.uk>

Fix the following warnings:
WARNING: vmlinux.o(.text+0xfe6711): Section mismatch in reference from the function cpufreq_unregister_driver() to the variable .cpuinit.data:cpufreq_cpu_notifier
WARNING: vmlinux.o(.text+0xfe68af): Section mismatch in reference from the function cpufreq_register_driver() to the variable .cpuinit.data:cpufreq_cpu_notifier
WARNING: vmlinux.o(.exit.text+0xc4fa): Section mismatch in reference from the function cpufreq_stats_exit() to the variable .cpuinit.data:cpufreq_stat_cpu_notifier

The warnings were casued by references to unregister_hotcpu_notifier()
from normal functions or exit functions.
This is flagged by modpost as a potential error because
it does not know that for the non HOTPLUG_CPU
scenario the unregister_hotcpu_notifier() is a nop.
Silence the warning by replacing the __initdata
annotation with a __refdata annotation.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDave Jones <davej@codemonkey.org.uk>

cpufreq_stats_free_table() mustn't be __cpuexit since it's called by the
__cpuinit cpufreq_stat_cpu_callback().

This patch fixes the following section mismatch reported by
Chris Clayton:

WARNING: vmlinux.o(.init.text+0x143dd): Section mismatch: reference to .exit.text:cpufreq_stats_free_table (between 'cpufreq_stat_cpu_callback' and 'cpufreq_stats_init')
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Cc: Chris Clayton <chris2553@googlemail.com>
Acked-by: NDave Jones <davej@codemonkey.org.uk>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* Stop referencing the callback directly from the __init and __exit
  functions of this driver, and instead explicitly call
  cpufreq_update_policy() et al. This enables the callback function
  to be marked as __cpuinit (and the notifier_block __cpuinitdata),
  thereby saving space when HOTPLUG_CPU=n. This also enables us to
  use other tricks to replace __cpuinit{data} in future.

* cpufreq_stats_free_table() is only called from __cpuinit or __exit
  marked functions, making it an ideal candidate for __cpuexit.

* Fix missing space in the module description
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Jones <davej@redhat.com>

sysfs is now completely out of driver/module lifetime game.  After
deletion, a sysfs node doesn't access anything outside sysfs proper,
so there's no reason to hold onto the attribute owners.  Note that
often the wrong modules were accounted for as owners leading to
accessing removed modules.

This patch kills now unnecessary attribute->owner.  Note that with
this change, userland holding a sysfs node does not prevent the
backing module from being unloaded.

For more info regarding lifetime rule cleanup, please read the
following message.

  http://article.gmane.org/gmane.linux.kernel/510293

(tweaked by Greg to not delete the field just yet, to make it easier to
merge things properly.)
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>