cpufreq: cpu0: Fix mistake in Documentation example

"clock-latency" is incorrectly written as "transition-latency" in an example
present in Documentation of cpufreq-cpu0. Fix it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Documentation: Fix cpufreq_frequency_table name

At few places in documentation cpufreq_frequency_table is written as
cpufreq_freq_table. Fix these.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: cpufreq-cpu0: No need to check cpu number in init()

It is not possible for init() to be called for any cpu other than cpu0. During
bootup whatever cpu is used to boot system will be assigned as cpu0. And later
on policy->cpu can only change if we hotunplug all cpus first and then hotplug
them back in different order, which isn't possible (system requires atleast one
cpu to be up always :)).

Though I can see one situation where policy->cpu can be different then zero.
- Hot-unplug cpu 0.
- rmmod cpufreq-cpu0 module
- insmod it back
- hotplug cpu 0 again.

Here, policy->cpu would be different. But the driver doesn't have any dependency
on cpu0 as such. We don't mind which cpu of a system is policy->cpu and so this
check is just not required.

Remove it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: cpufreq-cpu0: Call CPUFREQ_POSTCHANGE notifier for failure cases too

Currently we are simply returning from target() if we encounter some error after
broadcasting CPUFREQ_PRECHANGE notifier. Which looks to be wrong as others might
depend on POSTCHANGE notifier for their functioning.

So, better broadcast CPUFREQ_POSTCHANGE notifier for these failure cases too,
but with old frequency.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Notify all policy->cpus in cpufreq_notify_transition()

policy->cpus contains all online cpus that have single shared clock line. And
their frequencies are always updated together.

Many SMP system's cpufreq drivers take care of this in individual drivers but
the best place for this code is in cpufreq core.

This patch modifies cpufreq_notify_transition() to notify frequency change for
all cpus in policy->cpus and hence updates all users of this API.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Don't check if cpu is online/offline for cpufreq callbacks

cpufreq layer doesn't call cpufreq driver's callback for any offline
CPU and so checking that isn't useful.

Lets get rid of it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: drivers: don't check range of target freq in .target()

Cpufreq core checks the range of target_freq before calling driver->target() and
so we don't need to do it again.

Remove it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: drivers: Remove unnecessary assignments of policy-> members

Some assignments of policy-> min/max/cur/cpuinfo.min_freq/cpuinfo.max_freq
aren't required as part of it is done by cpufreq driver or cpufreq core.

Remove them.

At some places we merge multiple lines together too.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: ARM big LITTLE: Add generic cpufreq driver and its DT glue

big LITTLE is ARM's new Architecture focussing power/performance needs of modern
world. More information about big LITTLE can be found here:

http://www.arm.com/products/processors/technologies/biglittleprocessing.php
http://lwn.net/Articles/481055/

In order to keep cpufreq support for all big LITTLE platforms simple/generic,
this patch tries to add a generic cpufreq driver layer for all big LITTLE
platforms.

The driver is divided into two parts:
- Core driver: Generic and shared across all big LITTLE SoC's
- Glue drivers: Per platform drivers providing ops to the core driver

This patch adds in a generic glue driver which would extract information from
Device Tree.

Future SoC's can either reuse the DT glue or write their own depending on the
need.

Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / BGRT: Don't let users configure BGRT on non X86 systems

Fengguang Wu's 0-Day kernel build testing backend found the
following build error for an allmodconfig build on ia64:

   drivers/built-in.o: In function `show_yoffset':
>> bgrt.c:(.text+0xe5a71): undefined reference to `bgrt_tab'
>> bgrt.c:(.text+0xe5a91): undefined reference to `bgrt_tab'
   drivers/built-in.o: In function `show_xoffset':
>> bgrt.c:(.text+0xe5b51): undefined reference to `bgrt_tab'
>> bgrt.c:(.text+0xe5b71): undefined reference to `bgrt_tab'
   drivers/built-in.o: In function `show_type':
>> bgrt.c:(.text+0xe5c31): undefined reference to `bgrt_tab'
   drivers/built-in.o:bgrt.c:(.text+0xe5c51): more undefined references to `bgrt_tab' follow
   drivers/built-in.o: In function `bgrt_init':
   bgrt.c:(.init.text+0x8931): undefined reference to `bgrt_image'
   bgrt.c:(.init.text+0x8932): undefined reference to `bgrt_image_size'
   bgrt.c:(.init.text+0x8950): undefined reference to `bgrt_image'
   bgrt.c:(.init.text+0x8960): undefined reference to `bgrt_image_size'

The problem is that all these undefined names are provided by
arch/x86/platform/efi/efi-bgrt.c - which is obviously not available
to the ia64 build.

It doesn't seem useful to provide the BGRT support for Itanium
(many systems are headless and have no graphics at all). So
just don't let users configure this driver on non-X86 machines.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge branch 'acpi-fixes' into linux-next

* acpi-fixes:
  ACPI / BGRT: Don't let users configure BGRT on non X86 systems
Merge branch 'pm-cpufreq-next' into linux-next

* pm-cpufreq-next:
  cpufreq: ARM big LITTLE: Add generic cpufreq driver and its DT glue
  cpufreq: drivers: Remove unnecessary assignments of policy-> members
  cpufreq: drivers: don't check range of target freq in .target()
  cpufreq: Don't check if cpu is online/offline for cpufreq callbacks
  cpufreq: Notify all policy->cpus in cpufreq_notify_transition()
  cpufreq: cpufreq-cpu0: Call CPUFREQ_POSTCHANGE notifier for failure cases too
  cpufreq: cpufreq-cpu0: No need to check cpu number in init()
  cpufreq: Documentation: Fix cpufreq_frequency_table name
  cpufreq: cpu0: Fix mistake in Documentation example