Notifiers are required only for conservative governor and the common
governor code is unnecessarily polluted with that. Handle that from
cs_init/exit() instead of cpufreq_governor_dbs().
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq_update_policy() was kept as a separate routine earlier as it was
handling migration of sysfs directories, which isn't the case anymore.
It is only updating policy->cpu now and is called by a single caller.

The WARN_ON() isn't really required anymore, as we are just updating the
cpu now, not moving the sysfs directories.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

__cpufreq_remove_dev_finish() is doing two things today:
- Restarts the governor if some CPUs from concerned policy are still
  online.
- Frees the policy if all CPUs are offline.

The first task of restarting the governor can be moved to
__cpufreq_remove_dev_prepare() to restart the governor early. There is
no race between _prepare() and _finish() as they would be handling
completely different cases. _finish() will only be required if we are
going to free the policy and that has nothing to do with restarting the
governor.
Original-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq_policy_put_kobj() is actually part of freeing the policy and can
be called from cpufreq_policy_free() directly instead of a separate
call.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

policy->kobj is required to be initialized once in the lifetime of a
policy.  Currently we are initializing it from __cpufreq_add_dev() and
that doesn't look to be the best place for doing so as we have to do
this on special cases (like: !recover_policy).

We can initialize it from a more obvious place cpufreq_policy_alloc()
and that will make code look cleaner, specially the error handling part.

The error handling part of __cpufreq_add_dev() was doing almost the same
thing while recover_policy is true or false. Fix that as well by always
calling cpufreq_policy_put_kobj() with an additional parameter to skip
notification part of it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

When we hot-unplug a cpu, we remove its sysfs cpufreq directory and if
the outgoing cpu was the owner of policy->kobj earlier then we migrate
the sysfs directory to under another online cpu.

There are few disadvantages this brings:
- Code Complexity
- Slower hotplug/suspend/resume
- sysfs file permissions are reset after all policy->cpus are offlined
- CPUFreq stats history lost after all policy->cpus are offlined
- Special management of sysfs stuff during suspend/resume

To overcome these, this patch modifies the way sysfs directories are
managed:
- Select sysfs kobjects owner while initializing policy and don't change
  it during hotplugs. Track it with kobj_cpu created earlier.

- Create symlinks for all related CPUs (can be offline) instead of
  affected CPUs on policy initialization and remove them only when the
  policy is freed.

- Free policy structure only on the removal of cpufreq-driver and not
  during hotplug/suspend/resume, detected by checking 'struct
  subsys_interface *' (Valid only when called from
  subsys_interface_unregister() while unregistering driver).

Apart from this, special care is taken to handle physical hoplug of CPUs
as we wouldn't remove sysfs links or remove policies on logical
hotplugs. Physical hotplug happens in the following sequence.

Hot removal:
- CPU is offlined first, ~ 'echo 0 >
  /sys/devices/system/cpu/cpuX/online'
- Then its device is removed along with all sysfs files, cpufreq core
  notified with cpufreq_remove_dev() callback from subsys-interface..

Hot addition:
- First the device along with its sysfs files is added, cpufreq core
  notified with cpufreq_add_dev() callback from subsys-interface..
- CPU is onlined, ~ 'echo 1 > /sys/devices/system/cpu/cpuX/online'

We call the same routines with both hotplug and subsys callbacks, and we
sense physical hotplug with cpu_offline() check in subsys callback. We
can handle most of the stuff with regular hotplug callback paths and
add/remove cpufreq sysfs links or free policy from subsys callbacks.
Original-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Later commits would change the way policies are managed today. Policies
wouldn't be freed on cpu hotplug (currently they aren't freed only for
suspend), and while the CPU is offline, the sysfs cpufreq files would
still be present.

User may accidentally try to update the sysfs files in following
directory: '/sys/devices/system/cpu/cpuX/cpufreq/'. And that would
result in undefined behavior as policy wouldn't be active then.

Apart from updating the store() routine, we also update __cpufreq_get()
which can call cpufreq_out_of_sync(). The later routine tries to update
policy->cur and starts notifying kernel about it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

During initialization and exit it is possible that the target pstate
might not actually be set. Furthermore, the result can be that the
driver and the processor are out of synch and, under some conditions,
the driver might never send the processor the proper target pstate.

This patch adds a bypass or do_checks flag to the call to
intel_pstate_set_pstate. If bypass, then specifically bypass clamp
checks and the do not send if it is the same as last time check. If
do_checks, then, and as before, do the current policy clamp checks,
and do not do actual send if the new target is the same as the old.
Signed-off-by: Doug Smythies <dsmythies@telus.net>
Reported-by: Marien Zwart <marien.zwart@gmail.com>
Reported-by: Alex Lochmann <alexander.lochmann@tu-dortmund.de>
Reported-by: Piotr Ko?aczkowski <pkolaczk@gmail.com>
Reported-by: Clemens Eisserer <linuxhippy@gmail.com>
Tested-by: Marien Zwart <marien.zwart@gmail.com>
Tested-by: Doug Smythies <dsmythies@telus.net>
[ rjw: Dropped pointless symbol definitions, rebased ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit ce717613 (intel_pstate: Turn per cpu printk into pr_debug)
turned per cpu printk into pr_debug.  However, only half of the change
was done, introducing an inconsistency between entry and exit from
driver pstate control.  This patch changes the exit message to pr_debug
also.

The various messages are inconsistent with respect to any identifier
text that can be used to help isolate the desired information from a
huge log.  This patch makes a consistent identifier portion of the
string.

Amends: ce717613 (intel_pstate: Turn per cpu printk into pr_debug)
Signed-off-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

In order to prepare for the next few commits, that will stop migrating
sysfs files on cpu hotplug, this patch starts managing sysfs-cpu
separately.

The behavior is still the same as we are still migrating sysfs files on
hotplug, later commits would change that.
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Later commits would change the way policies are managed today. Policies
wouldn't be freed on cpu hotplug (currently they aren't freed on
suspend), and while the CPU is offline, the sysfs cpufreq files would
still be present.

Because we don't mark policy->governor as NULL, it still contains
pointer of the last used governor. And if the governor is removed, while
all the CPUs of a policy are hotplugged out, this pointer wouldn't be
valid anymore. And if we try to read the 'scaling_governor', etc.  from
sysfs, it will result in kernel OOPs.

To prevent this, mark policy->governor as NULL for all inactive policies
while the governor is removed from kernel.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

History of which governor was used last is common to all CPUs within a
policy and maintaining it per-cpu isn't the best approach for sure.

Apart from wasting memory, this also increases the complexity of
managing this data structure as it has to be updated for all CPUs.

To make that somewhat simpler, lets store this information in a new
field 'last_governor' in struct cpufreq_policy and update it on removal
of last cpu of a policy.

As a side-effect it also solves an old problem, consider a system with
two clusters 0 & 1. And there is one policy per cluster.

Cluster 0: CPU0 and 1.
Cluster 1: CPU2 and 3.

 - CPU2 is first brought online, and governor is set to performance
   (default as cpufreq_cpu_governor wasn't set).
 - Governor is changed to ondemand.
 - CPU2 is taken offline and cpufreq_cpu_governor is updated for CPU2.
 - CPU3 is brought online.
 - Because cpufreq_cpu_governor wasn't set for CPU3, the default governor
   performance is picked for CPU3.

This patch fixes the bug as we now have a single variable to update for
policy.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

We reach here while adding policy for a CPU and enter into the 'if'
block only if a policy already exists for the CPU.

As cpufreq_cpu_data is set for all policy->related_cpus now, when the
policy is first added, we can use that to find the CPU's policy instead
of traversing the list of all active policies.
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

We can extract the same information from cpufreq_cpu_data as it is also
available for inactive policies now. And so don't need
cpufreq_cpu_data_fallback anymore.

Also add a WARN_ON() for the case where we try to restore from an active
policy.
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Now that we can check policy->cpus to find if policy is active or not,
we don't need to clean cpufreq_cpu_data and delete policy from the list
on light weight tear down of policies (like in suspend).

To make it consistent and clean, set cpufreq_cpu_data for all related
CPUs when the policy is first created and clean it only while it is
freed.

Also update cpufreq_cpu_get_raw() to check if cpu is part of
policy->cpus mask, so that we don't end up getting policies for offline
CPUs.

In order to make sure that no users of 'policy' are using an inactive
policy, use cpufreq_cpu_get_raw() instead of directly accessing
cpufreq_cpu_data.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

policy->cpus is cleared unconditionally now on hotplug-out of a CPU and
it can be checked to know if a policy is active or not. Create helper
routines to iterate over all active/inactive policies, based on
policy->cpus field.

Replace all instances of for_each_policy() with for_each_active_policy()
to make them iterate only for active policies. (We haven't made changes
yet to keep inactive policies in the same list, but that will be
followed in a later patch).
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

With the addition of switcher code, there's compile-time dependency on
BIG_LITTLE to get arm_big_little driver compiling on ARM64. Since ARM64
will never add support for bL switcher, it's better to remove the
dependency so that the driver can be reused on ARM64 platforms.

This patch adds stubs to remove BIG_LITTLE dependency in the driver.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 007bea09 (intel_pstate: Add setting voltage value for
baytrail P states.) introduced byt_set_pstate() with the assumption that
it would always be run by the CPU whose MSR is to be written by it.  It
turns out, however, that is not always the case in practice, so modify
byt_set_pstate() to enforce the MSR write done by it to always happen on
the right CPU.

Fixes: 007bea09 (intel_pstate: Add setting voltage value for baytrail P states.)
Signed-off-by: Joe Konno <joe.konno@intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

We clear policy->cpus mask while CPUs are hotplugged out. We do it for all CPUs
except the last CPU of the policy. I don't remember what the rationale behind
that was, but I couldn't think of anything that will break if we remove this
conditional clearing and always clear policy->cpus.

The benefit we get out of it is, we can know if a policy is active or not by
checking if this field is empty or not. That will be used by later commits.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

There are two cases when we may try to add CPUs we're already handling:
 - On boot, the first cpu has marked all policy->cpus managed and so we
   will find policy for all other policy->cpus later on.
 - When a managed cpu is hotplugged out and later brought back in.

Currently, separate paths and checks take care of the two.  While the
first one is detected by testing cpu against 'policy->cpus', the other
one is detected by testing cpu against 'policy->related_cpus'.

We can handle them both via a single path and there is no need to do
special checking for the first one.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
[ rjw: Changelog, comments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Simply returning here with an error is not enough. It shouldn't be allowed at
all to try calling cpufreq_cpu_get() for an invalid CPU.

Add a WARN here to make it clear that it wouldn't be acceptable at all.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq_add_dev() is an unnecessary wrapper over __cpufreq_add_dev(). Merge
them.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

This clearly states what the code inside these routines is doing and how these
must be used.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The file 'Documentation/cpu-freq/user-guide.txt' has duplicate
description of sysfs interface 'scaling_driver'.

[first]
scaling_driver :                this file shows what cpufreq driver is
				used to set the frequency on this CPU

[second]
scaling_driver :                Hardware driver for cpufreq.

Although this does not affect anything, I think we should only have
one. so delete the second one because the first one is described in
more detail.
Signed-off-by: Wang Long <long.wanglong@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The intel_pstate driver is difficult to debug and investigate without tsc.

Also, it is likely use of tsc, and some version of C0 percentage,
will be re-introdcued in futute.

There have also been occasions where it is desirebale to know, and
confirm, the previous target pstate.

This patch brings back tsc, adds previous target pstate,
and adds both to the trace data collection.
Signed-off-by: Doug Smythies <dsmythies@telus.net>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The "cpu-cluster.<n>" used to get the cluster clock is not used by any
platform. Moreover __of_clk_get_by_name used in clk_get return error if
the "clock-names" in the DT doesn't match this string. When using DT,
it's not compulsory to specify the clock name unless there are multiple
clock input entries in the consumer.

This patch removes the unused clock string from the driver.
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The actual frequency is set through "clk_change_rate" which is void
function. If the underlying hardware fails and returns error, the error
is lost in the clk layer. In order to track such failures, we need to
read back the frequency(just the cached value as clk_recalc called after
clk->ops->set_rate gets the frequency)

This patch adds check to see if the frequency is set correctly or if
they were any hardware failures and sends the appropriate errors to the
cpufreq core.
Reviewed-by: Michael Turquette <mike.turquette@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

pxa255_run_freqs and pxa255_turbo_freqs are only read.
This patch updates arrays declaration, find_freq_tables()
and its callsites.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

typedef is not really useful here. Replace it by structure
to improve readability. typedef should only be used in some cases.
(See Documentation/CodingStyle Chapter 5 for details).
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull ext4 fixes from Ted Ts'o:
 "Some miscellaneous bug fixes and some final on-disk and ABI changes
  for ext4 encryption which provide better security and performance"

* tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix growing of tiny filesystems
  ext4: move check under lock scope to close a race.
  ext4: fix data corruption caused by unwritten and delayed extents
  ext4 crypto: remove duplicated encryption mode definitions
  ext4 crypto: do not select from EXT4_FS_ENCRYPTION
  ext4 crypto: add padding to filenames before encrypting
  ext4 crypto: simplify and speed up filename encryption

Pull drm fixes from Dave Airlie:
 "One intel fix, one rockchip fix, and a bunch of radeon fixes for some
  regressions from audio rework and vm stability"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/i915/chv: Implement WaDisableShadowRegForCpd
  drm/radeon: fix userptr return value checking (v2)
  drm/radeon: check new address before removing old one
  drm/radeon: reset BOs address after clearing it.
  drm/radeon: fix lockup when BOs aren't part of the VM on release
  drm/radeon: add SI DPM quirk for Sapphire R9 270 Dual-X 2G GDDR5
  drm/radeon: adjust pll when audio is not enabled
  drm/radeon: only enable audio streams if the monitor supports it
  drm/radeon: only mark audio as connected if the monitor supports it (v3)
  drm/radeon/audio: don't enable packets until the end
  drm/radeon: drop dce6_dp_enable
  drm/radeon: fix ordering of AVI packet setup
  drm/radeon: Use drm_calloc_ab for CS relocs
  drm/rockchip: fix error check when getting irq
  MAINTAINERS: add entry for Rockchip drm drivers

Just a single intel fix
* tag 'drm-intel-fixes-2015-04-30' of git://anongit.freedesktop.org/drm-intel:
  drm/i915/chv: Implement WaDisableShadowRegForCpd

one fix and maintainers update
* 'drm-next0420' of https://github.com/markyzq/kernel-drm-rockchip:
  drm/rockchip: fix error check when getting irq
  MAINTAINERS: add entry for Rockchip drm drivers

Pull SCSI fixes from James Bottomley:
 "This is three logical fixes (as 5 patches).

  The 3ware class of drivers were causing an oops with multiqueue by
  tearing down the command mappings after completing the command (where
  the variables in the command used to tear down the mapping were
  no-longer valid).  There's also a fix for the qnap iscsi target which
  was choking on us sending it commands that were too long and a fix for
  the reworked aha1542 allocating GFP_KERNEL under a lock"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  3w-9xxx: fix command completion race
  3w-xxxx: fix command completion race
  3w-sas: fix command completion race
  aha1542: Allocate memory before taking a lock
  SCSI: add 1024 max sectors black list flag

Pull slave dmaengine fixes from Vinod Koul:
 "Here are the fixes in dmaengine subsystem for rc2:

   - privatecnt fix for slave dma request API by Christopher

   - warn fix for PM ifdef in usb-dmac by Geert

   - fix hardware dependency for xgene by Jean"

* 'next' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: increment privatecnt when using dma_get_any_slave_channel
  dmaengine: xgene: Set hardware dependency
  dmaengine: usb-dmac: Protect PM-only functions to kill warning

Pull powerpc fixes from Michael Ellerman:
 - build fix for SMP=n in book3s_xics.c
 - fix for Daniel's pci_controller_ops on powernv.
 - revert the TM syscall abort patch for now.
 - CPU affinity fix from Nathan.
 - two EEH fixes from Gavin.
 - fix for CR corruption from Sam.
 - selftest build fix.

* tag 'powerpc-4.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
  powerpc/powernv: Restore non-volatile CRs after nap
  powerpc/eeh: Delay probing EEH device during hotplug
  powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state()
  powerpc/pseries: Correct cpu affinity for dlpar added cpus
  selftests/powerpc: Fix the pmu install rule
  Revert "powerpc/tm: Abort syscalls in active transactions"
  powerpc/powernv: Fix early pci_controller_ops loading.
  powerpc/kvm: Fix SMP=n build error in book3s_xics.c

The estimate of necessary transaction credits in ext4_flex_group_add()
is too pessimistic. It reserves credit for sb, resize inode, and resize
inode dindirect block for each group added in a flex group although they
are always the same block and thus it is enough to account them only
once. Also the number of modified GDT block is overestimated since we
fit EXT4_DESC_PER_BLOCK(sb) descriptors in one block.

Make the estimation more precise. That reduces number of requested
credits enough that we can grow 20 MB filesystem (which has 1 MB
journal, 79 reserved GDT blocks, and flex group size 16 by default).
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>

fallocate() checks that the file is extent-based and returns
EOPNOTSUPP in case is not. Other tasks can convert from and to
indirect and extent so it's safe to check only after grabbing
the inode mutex.
Signed-off-by: Davide Italiano <dccitaliano@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org