Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This fixes below build error when CONFIG_REGMAP=y && CONFIG_REGMAP_SPI=m

ERROR: "regmap_async_complete_cb" [drivers/base/regmap/regmap-spi.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This fixes:

drivers/base/regmap/regmap.c: In function 'regmap_async_complete_cb':
drivers/base/regmap/regmap.c:1656:3: error: 'TASK_NORMAL' undeclared (first use in this function)
drivers/base/regmap/regmap.c:1656:3: note: each undeclared identifier is reported only once for each function it appears in
drivers/base/regmap/regmap.c: In function 'regmap_async_complete':
drivers/base/regmap/regmap.c:1688:2: error: 'TASK_UNINTERRUPTIBLE' undeclared (first use in this function)
drivers/base/regmap/regmap.c:1688:2: error: implicit declaration of function 'schedule'

An alternative might be to adjust linux/wait.h to include linux/sched.h,
but since that hasn't been done before, I assume we're consciously
avoiding doing that.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some use cases like firmware download can transfer a lot of data in quick
succession. With high speed buses these use cases can benefit from having
multiple transfers scheduled at once since this allows the bus to minimise
the delay between transfers.

Support this by adding regmap_raw_write_async(), allowing raw transfers to
be scheduled, and regmap_async_complete() to wait for them to finish.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This commit is a preparatory commit to provide "no-bus" configuration
option for regmap API. It adds necessary plumbing needed to have the
ability to provide user define register write function.
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This commit is a preparatory commit to provide "no-bus" configuration
option for regmap API. It adds necessary plumbing needed to have the
ability to provide user define register read function.
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Currently, the PM core disables runtime PM for all devices right
after executing subsystem/driver .suspend() callbacks for them
and re-enables it right before executing subsystem/driver .resume()
callbacks for them.  This may lead to problems when there are
two devices such that the .suspend() callback executed for one of
them depends on runtime PM working for the other.  In that case,
if runtime PM has already been disabled for the second device,
the first one's .suspend() won't work correctly (and analogously
for resume).

To make those issues go away, make the PM core disable runtime PM
for devices right before executing subsystem/driver .suspend_late()
callbacks for them and enable runtime PM for them right after
executing subsystem/driver .resume_early() callbacks for them.  This
way the potential conflitcs between .suspend_late()/.resume_early()
and their runtime PM counterparts are still prevented from happening,
but the subtle ordering issues related to disabling/enabling runtime
PM for devices during system suspend/resume are much easier to avoid.
Reported-and-tested-by: NJan-Matthias Braun <jan_braun@gmx.net>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@deeprootsystems.com>
Cc: 3.4+ <stable@vger.kernel.org>

Local variable 'error' in dev_pm_qos_add_ancestor_request() need
not contain error codes only, so rename it to 'ret'.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Where we can pass in LOOKUP_DIRECTORY or LOOKUP_REVAL. Any other flags
passed in here are currently ignored.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We never really clarified if unmap could be done in atomic context.
But since mapping might require sleeping, this implies mutex in use
to synchronize mapping/unmapping, so unmap could sleep as well.  Add
a might_sleep() to clarify this.
Signed-off-by: NRob Clark <rob@ti.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: NSumit Semwal <sumit.semwal@linaro.org>

We need a node which only contains movable memory.  This feature is very
important for node hotplug.  If a node has normal/highmem, the memory may
be used by the kernel and can't be offlined.  If the node only contains
movable memory, we can offline the memory and the node.

All are prepared, we can actually introduce N_MEMORY.
add CONFIG_MOVABLE_NODE make we can use it for movable-dedicated node

[akpm@linux-foundation.org: fix Kconfig text]
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Tested-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

N_HIGH_MEMORY stands for the nodes that has normal or high memory.
N_MEMORY stands for the nodes that has any memory.

The code here need to handle with the nodes which have memory, we should
use N_MEMORY instead.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: NHillf Danton <dhillf@gmail.com>
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Lin Feng <linfeng@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add online_movable and online_kernel for logic memory hotplug.  This is
the dynamic version of "movablecore" & "kernelcore".

We have the same reason to introduce it as to introduce "movablecore" &
"kernelcore".  It has the same motive as "movablecore" & "kernelcore", but
it is dynamic/running-time:

o We can configure memory as kernelcore or movablecore after boot.

  Userspace workload is increased, we need more hugepage, we can't use
  "online_movable" to add memory and allow the system use more
  THP(transparent-huge-page), vice-verse when kernel workload is increase.

  Also help for virtualization to dynamic configure host/guest's memory,
  to save/(reduce waste) memory.

  Memory capacity on Demand

o When a new node is physically online after boot, we need to use
  "online_movable" or "online_kernel" to configure/portion it as we
  expected when we logic-online it.

  This configuration also helps for physically-memory-migrate.

o all benefit as the same as existed "movablecore" & "kernelcore".

o Preparing for movable-node, which is very important for power-saving,
  hardware partitioning and high-available-system(hardware fault
  management).

(Note, we don't introduce movable-node here.)

Action behavior:
When a memoryblock/memorysection is onlined by "online_movable", the kernel
will not have directly reference to the page of the memoryblock,
thus we can remove that memory any time when needed.

When it is online by "online_kernel", the kernel can use it.
When it is online by "online", the zone type doesn't changed.

Current constraints:
Only the memoryblock which is adjacent to the ZONE_MOVABLE
can be online from ZONE_NORMAL to ZONE_MOVABLE.

[akpm@linux-foundation.org: use min_t, cleanups]
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

use [index] = init_value
use N_xxxxx instead of hardcode.

Make it more readability and easier to add new state.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

register_node() is defined as extern in include/linux/node.h.  But the
function is only called from register_one_node() in driver/base/node.c.

So the patch defines register_node() as static.
Signed-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When calling unregister_node(), the function shows following message at
device_release().

"Device 'node2' does not have a release() function, it is broken and must
be fixed."

The reason is node's device struct does not have a release() function.

So the patch registers node_device_release() to the device's release()
function for suppressing the warning message.  Additionally, the patch
adds memset() to initialize a node struct into register_node().  Because
the node struct is part of node_devices[] array and it cannot be freed by
node_device_release().  So if system reuses the node struct, it has a
garbage.
Signed-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We use a static array to store struct node.  In many cases, we don't have
too many nodes, and some memory will be unused.  Convert it to per-device
dynamically allocated memory.
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When calling remove_memory_block(), the function shows following message
at device_release().

"Device 'memory528' does not have a release() function, it is broken and
must be fixed."

The reason is memory_block's device struct does not have a release()
function.

So the patch registers memory_block_release() to the device's release()
function for suppressing the warning message.  Additionally, the patch
moves kfree(mem) into the release function since the release function is
prepared as a means to free a memory_block struct.
Signed-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This commit changes the CMA early initialization code to use phys_addr_t
for representing physical addresses instead of unsigned long.

Without this change, among other things, dma_declare_contiguous() simply
discards any memory regions whose address is not representable as unsigned
long.

This is a problem on 32-bit PAE machines where unsigned long is 32-bit
but physical address space is larger.
Signed-off-by: NVitaly Andrianov <vitalya@ti.com>
Signed-off-by: NCyril Chemparathy <cyril@ti.com>
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>

Avoid doing a linear scan of the entire register map for each read() of
the debugfs register dump by recording the offsets where valid registers
exist when we first read the registers file. This assumes the set of
valid registers never changes, if this is not the case invalidation of
the cache will be required.

This could be further improved for large blocks of contiguous registers
by calculating the register we will read from within the block - currently
we do a linear scan of the block. An rbtree may also be worthwhile.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

In preparation for doing things a bit more quickly than a linear scan
factor out the initial seek from the debugfs register dump.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If count is less than the size of a register then we may hit integer
wraparound when trying to move backwards to check if we're still in
the buffer. Instead move the position forwards to check if it's still
in the buffer, we are unlikely to be able to allocate a buffer
sufficiently big to overflow here.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org

No point in calculating them every time.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Remove conditional code based on CONFIG_HOTPLUG being false.  It's
always on now in preparation of it going away as an option.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Drivers usually expect that the devices they are supposed to handle
will be operational when their .probe() routines are called, but that
need not be the case on some ACPI-based systems with ACPI-based
device enumeration where the BIOSes don't put devices into D0 by
default.  To work around this problem it is sufficient to change
bus type .probe() routines to ensure that devices will be powered
on before the drivers' .probe() routines run (and their .remove()
and .shutdown() routines accordingly).

Modify platform_drv_probe() to run acpi_dev_pm_attach() for devices
whose ACPI handles are present, so that ACPI power management is used
to change their power states.  Analogously, modify
platform_drv_remove() and platform_drv_shutdown() to call
acpi_dev_pm_detach() for those devices, so that they are not subject
to ACPI PM any more.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

dma_common_get_sgtable() function doesn't depend on
ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY, so it must not be compiled
conditionally.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Nothing outside of drivers/base/core.c references this function.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

syscore_shutdown uses initcall_debug to control the debug info output.
It’s a good programming. But device_shutdown doesn’t. The patch changes
device_shutdown to follow the style.
Signed-off-by: NYanmin Zhang <yanmin_zhang@linux.intel.com>
Signed-off-by: NShuoX Liu <shuox.liu@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

PM QoS flags have to be handled by dev_pm_qos_constraints_destroy()
in the same way as PM QoS resume latency constraints.  That is, if
they have been exposed to user space, they have to be hidden from it
and the list of flags requests has to be flushed before destroying
the device's PM QoS object.  Make that happen.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

dev_pm_qos_add_request() can return 0, 1, or a negative error code,
therefore the correct error test is "if (error < 0)." Checking just for
non-zero return code leads to erroneous setting of the req->dev pointer
to NULL, which then leads to a repeated call to
dev_pm_qos_add_ancestor_request() in st1232_ts_irq_handler(). This in turn
leads to an Oops, when the I2C host adapter is unloaded and reloaded again
because of the inconsistent state of its QoS request list.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Many of the regmap enabled drivers implementing one or more of the
readable, writeable, volatile and precious methods use the same code
pattern:

	return ((reg >= X && reg <= Y) || (reg >= W && reg <= Z) || ...)

Switch to a data driven approach, using tables to describe
readable/writeable/volatile and precious registers ranges instead.
The table based check can still be overridden by passing the usual function
pointers via struct regmap_config.
Signed-off-by: NDavide Ciminaghi <ciminaghi@gnudd.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The current platform device creation and registration code in
acpi_create_platform_device() is quite convoluted.  This function
takes an ACPI device node as an argument and eventually calls
platform_device_register_resndata() to create and register a
platform device object on the basis of the information contained
in that code.  However, it doesn't associate the new platform
device with the ACPI node directly, but instead it relies on
acpi_platform_notify(), called from within device_add(), to find
that ACPI node again with the help of acpi_platform_find_device()
and acpi_platform_match() and then attach the new platform device
to it.  This causes an additional ACPI namespace walk to happen and
is clearly suboptimal.

Use the observation that it is now possible to initialize the ACPI
handle of a device before calling device_add() for it to make this
code more straightforward.  Namely, add a new field to struct
platform_device_info allowing us to pass the ACPI handle of interest
to platform_device_register_full(), which will then use it to
initialize the new device's ACPI handle before registering it.
This will cause acpi_platform_notify() to use the ACPI handle from
the device structure directly instead of using the .find_device()
routine provided by the device's bus type.  In consequence,
acpi_platform_bus, acpi_platform_find_device(), and
acpi_platform_match() are not necessary any more, so remove them.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Probably due to copy&paste, some stuff was simply forgotten.
Signed-off-by: NWolfram Sang <wolfram@the-dreams.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We hit an hang issue when removing a mmc device on Medfield Android phone by sysfs interface.

device_pm_remove will call pm_runtime_remove which would disable
runtime PM of the device. After that pm_runtime_get* or
pm_runtime_put* will be ignored. So if we disable the runtime PM
before device really be removed, drivers' _remove callback may
access HW even pm_runtime_get* fails. That is bad.

Consider below call sequence when removing a device:
device_del => device_pm_remove
             => class_intf->remove_dev(dev, class_intf)  => pm_runtime_get_sync/put_sync
             => bus_remove_device => device_release_driver => pm_runtime_get_sync/put_sync

remove_dev might call pm_runtime_get_sync/put_sync.
Then, generic device_release_driver also calls pm_runtime_get_sync/put_sync.
Since device_del => device_pm_remove firstly, later _get_sync wouldn't really wake up the device.

I git log -p to find the patch which moves the calling to device_pm_remove ahead.
It's below patch:

commit  775b64d2
Author: Rafael J. Wysocki <rjw@sisk.pl>
Date:   Sat Jan 12 20:40:46 2008 +0100

     PM: Acquire device locks on suspend

     This patch reorganizes the way suspend and resume notifications are
     sent to drivers.  The major changes are that now the PM core acquires
     every device semaphore before calling the methods, and calls to
     device_add() during suspends will fail, while calls to device_del()
     during suspends will block.

     It also provides a way to safely remove a suspended device with the
     help of the PM core, by using the device_pm_schedule_removal() callback
     introduced specifically for this purpose, and updates two drivers (msr
     and cpuid) that need to use it.

As device_pm_schedule_removal is deleted by another patch, we need also revert other parts of the patch,
i.e. move the calling of device_pm_remove after the calling to bus_remove_device.
Signed-off-by: NLongX Zhang <longx.zhang@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When PM runtime is enabled in DaVinci and the machine migrates to
common clk framework, the clk_enable() gets called without
clk_prepare(). This patch is to fix this issue so that PM run
time can inter work with common clk framework.
Signed-off-by: NMurali Karicheri <m-karicheri2@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The callback function of call_rcu() just calls a kfree(), so we
can use kfree_rcu() instead of call_rcu() + callback function.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently the opp_find* functions return -ENODEV when:
a) it cant find a device (e.g. request for an OPP search on device
   which was not registered)
b) When it cant find a match for the search strategy used

This makes life a little in-efficient for users such as devfreq
to make reasonable judgement before switching search strategies.

So, standardize the return results as following:
 -EINVAL for bad pointer parameters
 -ENODEV when device cannot be found
 -ERANGE when search fails

This has the following benefit for devfreq implementation:
The search fails when an unregistered device pointer is provided.
This is a trigger to change the search direction and search for
a better fit, however, if we cannot differentiate between a valid
search range failure Vs an unregistered device, second search goes
through the same fail return condition. This can be avoided by
appropriate handling of error return code.

With this change, we also fix devfreq for the improved search
strategy with updated error code.
Signed-off-by: NNishanth Menon <nm@ti.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Acked-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Export the OPP functions for use by driver modules.

Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Kevin Hilman <khilman@ti.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

[nm@ti.com: expansion of functions exported]
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NLiam Girdwood <lrg@ti.com>
Acked-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

synchronize_rcu() blocks the caller of opp_enable/disbale
for a complete grace period. This blocking duration prevents
any intensive use of the functions. Replace synchronize_rcu()
by call_rcu() which will call our function for freeing the old
opp element.

The duration of opp_enable() and opp_disable() will be no more
dependant of the grace period.
Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>