PM / devfreq: Remove "select SRCU"

Now that the SRCU Kconfig option is unconditionally selected, there is
no longer any point in selecting it. Therefore, remove the "select SRCU"
Kconfig statements.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: mediatek: Introduce MediaTek CCI devfreq driver

We introduce a devfreq driver for the MediaTek Cache Coherent Interconnect
(CCI) used by some MediaTek SoCs.

In this driver, we use the passive devfreq driver to get target frequencies
and adjust voltages accordingly. In MT8183 and MT8186, the MediaTek CCI
is supplied by the same regulators with the little core CPUs.

Signed-off-by: Jia-Wei Chang <jia-wei.chang@mediatek.com>
Signed-off-by: Johnson Wang <johnson.wang@mediatek.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: sun8i: addd COMMON_CLK dependency

Compile-testing the driver without CONFIG_COMMON_CLK causes
a link failure:

arm-linux-gnueabi-ld: drivers/devfreq/sun8i-a33-mbus.o: in function `sun8i_a33_mbus_remove':
sun8i-a33-mbus.c:(.text+0x450): undefined reference to `clk_rate_exclusive_put'
arm-linux-gnueabi-ld: sun8i-a33-mbus.c:(.text+0x460): undefined reference to `clk_rate_exclusive_put'
arm-linux-gnueabi-ld: drivers/devfreq/sun8i-a33-mbus.o: in function `sun8i_a33_mbus_probe':
sun8i-a33-mbus.c:(.text+0x85c): undefined reference to `clk_rate_exclusive_get'
arm-linux-gnueabi-ld: sun8i-a33-mbus.c:(.text+0x878): undefined reference to `clk_rate_exclusive_get'

Fixes: 8bfd4858b4bb ("PM / devfreq: Add a driver for the sun8i/sun50i MBUS")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: Add a driver for the sun8i/sun50i MBUS

This driver works by adjusting the divider on the DRAM controller's
module clock. Thus there is no fixed set of OPPs, only "full speed" down
to "quarter speed" (or whatever the maximum divider is on that variant).

It makes use of the MDFS hardware in the MBUS, in "DFS" mode, which
takes care of updating registers during the critical section while DRAM
is inaccessible.

This driver should support several sunxi SoCs, starting with the A33,
which have a DesignWare DDR3 controller with merged PHY register space
and the matching MBUS register layout (so not A63 or later). However,
the driver has only been tested on the A64/H5, so those are the only
compatibles enabled for now.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: imx8m-ddrc: Remove DEVFREQ_GOV_SIMPLE_ONDEMAND dependency

The driver can't support simple ondemand governor due to missing
.get_dev_status() capability.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: Fix the wrong set_freq path for userspace governor in Kconfig

Fix the wrong set_freq path for userspace governor in Kconfig.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: tegra20: Deprecate in a favor of emc-stat based driver

Remove tegra20-devfreq in order to replace it with a EMC_STAT based
devfreq driver. Previously we were going to use MC_STAT based
tegra20-devfreq driver because EMC_STAT wasn't working properly, but
now that problem is resolved. This resolves complications imposed by
the removed driver since it was depending on both EMC and MC drivers
simultaneously.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: tegra20: Relax Kconfig dependency

The Tegra EMC driver now could be compiled as a loadable kernel module.
Currently devfreq driver depends on the EMC/MC drivers in Kconfig, and
thus, devfreq is forced to be a kernel module if EMC is compiled as a
module. This build dependency could be relaxed since devfreq driver
checks MC/EMC presence on probe, allowing kernel configuration where
devfreq is a built-in driver and EMC driver is a loadable module.
This change puts Tegra20 devfreq Kconfig entry on a par with the Tegra30
devfreq entry.

Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: Add generic imx bus scaling driver

Add initial support for dynamic frequency switching on pieces of the imx
interconnect fabric.

All this driver does is set a clk rate based on an opp table, it does
not map register areas.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Tested-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: exynos: Rename Exynos to lowercase

Fix up inconsistent usage of upper and lowercase letters in "Exynos"
name.

"EXYNOS" is not an abbreviation but a regular trademarked name.
Therefore it should be written with lowercase letters starting with
capital letter.

The lowercase "Exynos" name is promoted by its manufacturer Samsung
Electronics Co., Ltd., in advertisement materials and on website.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: rk3399_dmc: Add COMPILE_TEST and HAVE_ARM_SMCCC dependency

To build test, add COMPILE_TEST depedency to both ARM_RK3399_DMC_DEVFREQ
and DEVFREQ_EVENT_ROCKCHIP_DFI configuration. And ARM_RK3399_DMC_DEVFREQ
used the SMCCC interface so that add HAVE_ARM_SMCCC dependency to prevent
the build break.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: Add dynamic scaling for imx8m ddr controller

Add driver for dynamic scaling the DDR Controller on imx8m chips. Actual
frequency switching is implemented inside TF-A, this driver wraps the
SMC calls and synchronizes the clk tree.

The DRAM clocks on imx8m have the following structure (abridged):

+----------+ |\ +------+
| dram_pll |-------|M| dram_core | |
+----------+ |U|---------->| D |
/--|X| | D |
dram_alt_root | |/ | R |
| | C |
+---------+ | |
|FIX DIV/4| | |
+---------+ | |
composite: | | |
+----------+ | | |
| dram_alt |----/ | |
+----------+ | |
| dram_apb |-------------------->| |
+----------+ +------+

The dram_pll is used for higher rates and dram_alt is used for lower
rates. The dram_alt and dram_apb clocks are "imx composite" and their
parent can also be modified.

This driver will prepare/enable the new parents ahead of switching (so
that the expected roots are enabled) and afterwards it will call
clk_set_parent to ensure the parents in clock framework are up-to-date.

The driver relies on dram_pll dram_alt and dram_apb being marked with
CLK_GET_RATE_NOCACHE for rate updates.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
[cw00.choi: Edit the COMPILE_TEST module dependency in Kconfig]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: Fix Kconfig indentation

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: tegra: Add COMMON_CLK dependency

Compile-testing this driver fails if CONFIG_COMMON_CLK is not set:

drivers/devfreq/tegra30-devfreq.o: In function `tegra_devfreq_target':
tegra30-devfreq.c:(.text+0x164): undefined reference to `clk_set_min_rate'

Fixes: 35f8dbc72721 ("PM / devfreq: tegra: Enable COMPILE_TEST for the driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: Drop explicit selection of PM_OPP

CONFIG_PM_OPP is already selected by CONFIG_PM_DEVFREQ
since commit b9c69e043266 ("PM / devfreq: Add dependency on PM_OPP").
This means that individual drivers shouldn't "select PM_OPP" explicitly.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
[cw00.choi: Edit the patch title]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: tegra20: add COMMON_CLK dependency

Compile-testing the new driver on platforms without CONFIG_COMMON_CLK
leads to a link error:

drivers/devfreq/tegra20-devfreq.o: In function `tegra_devfreq_target':
tegra20-devfreq.c:(.text+0x288): undefined reference to `clk_set_min_rate'

Add a dependency on COMMON_CLK to avoid this.

Fixes: 1d39ee8dad6d ("PM / devfreq: Introduce driver for NVIDIA Tegra20")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: Introduce driver for NVIDIA Tegra20

Add devfreq driver for NVIDIA Tegra20 SoC's. The driver periodically
reads out Memory Controller counters and adjusts memory frequency based
on the memory clients activity.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
[Removed MAINTAINERS updates by MyungJoo so that it can be sent elsewhere.]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: tegra: Enable COMPILE_TEST for the driver

The driver's compilation doesn't have any specific dependencies, hence
the COMPILE_TEST option can be supported in Kconfig.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: tegra: Support Tegra30

The devfreq driver can be used on Tegra30 without any code change and
it works perfectly fine, the default Tegra124 parameters are good enough
for Tegra30.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
[Modified by MyungJoo to depends on Tegra30/114/124/210 only]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: tegra: Mark ACTMON's governor as immutable

The ACTMON's governor supports only the Tegra's devfreq device and there
is no need to use any other governor, hence let's mark Tegra governor as
immutable to permanently stick it with Tegra's devfreq device.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PM / devfreq: Add dependency on PM_OPP

The devfreq ues the OPP library to handle the voltage and frequency
for the device basically. This patch adds the dependency on CONFIG_PM_OPP
in order to prevent either the build break or the unknow behavior.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: rockchip: add PM_DEVFREQ_EVENT dependency

The newly added ARM_RK3399_DMC_DEVFREQ driver requires the
DEVFREQ_EVENT_ROCKCHIP_DFI driver and tries to turn that on through
a 'select' statement, and that in turn has a dependency on
PM_DEVFREQ_EVENT, which may be disabled here:

warning: (ARM_RK3399_DMC_DEVFREQ) selects DEVFREQ_EVENT_ROCKCHIP_DFI which has unmet direct dependencies (PM_DEVFREQ && PM_DEVFREQ_EVENT && ARCH_ROCKCHIP)

We probably want a 'depends on' here, but other drivers use 'select'
too, so for consistency I'm doing the same.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 5a893e31a636 (PM / devfreq: rockchip: add devfreq driver for rk3399 dmc)
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

partial revert of "PM / devfreq: Add COMPILE_TEST for build coverage"

This reverts the Tegra part of commit 797da5598f3a (PM / devfreq: Add
COMPILE_TEST for build coverage) that introduced a build failute in
in linux-next.

[ rjw: Changelog ]
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / devfreq: rockchip: add devfreq driver for rk3399 dmc

base on dfi result, we do ddr frequency scaling, register
dmc driver to devfreq framework, and use simple-ondemand
policy.

Signed-off-by: Lin Huang <hl@rock-chips.com>
Signed-off-by: MyngJoo Ham <myngjoo.ham@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>

PM / devfreq: fix Kconfig indent style

Use tab rather than space to indent, and tab + two spaces to indent
help message.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: Add COMPILE_TEST for build coverage

The SoC-specific devfreq and devfreq-event drivers can be build tested
on all architectures.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: make exynos-bus ARM_EXYNOS_BUS_DEVFREQ tristate

The Kconfig currently controlling compilation of this code is:

devfreq/Kconfig:config ARM_EXYNOS_BUS_DEVFREQ
devfreq/Kconfig: bool "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"

...meaning that it currently is not being built as a module by anyone.

Rather than rip out the existing modular code, Chanwoo indicated
that he'd rather see the driver offered as tristate.

I don't have the hardware for runtime validation, so this change
is only validated for compile and modpost.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: exynos: Remove unused exynos4/5 busfreq driver

This patch removes the unused exynos4/5 busfreq driver. Instead,
generic exynos-bus frequency driver support the all Exynos SoCs.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

PM / devfreq: exynos: Add support of bus frequency of sub-blocks using passive governor

This patch adds the support of bus frequency feature for sub-blocks which share
the one power line. If each bus depends on the power line, each bus is not able
to change the voltage by oneself. To optimize the power-consumption on runtime,
some buses using the same power line should change the source clock and
regulator at the same time. So, this patch uses the passive governor to support
the bus frequency for all buses which sharing the one power line.

For example,

Exynos3250 include the two power line for AXI buses as following:
: VDD_MIF : MIF (Memory Interface) provide the DMC (Dynamic Memory Controller)
with the power (regulator).
: VDD_INT : INT (Internal) provide the various sub-blocks with the power
(regulator).

Each bus is included in as follwoing block. In the case of VDD_MIF, only DMC bus
use the power line. So, there is no any depencency between buese. But, in the
case of VDD_INT, various buses share the one power line of VDD_INT. We need to
make the depenency between buses. When using passive governor, there is no
problem to support the bus frequency as DVFS for all buses. One bus should be
operated as the parent bus device which gathering the current load of INT block
and then decides the new frequency with some governors except of passive
governor. After deciding the new frequency by the parent bus device, the rest
bus devices will change the each source clock according to new frequency of the
parent bus device.

- MIF (Memory Interface) block
: VDD_MIF |--- DMC

- INT (Internal) block
: VDD_INT |--- LEFTBUS (parent)
|--- PERIL
|--- MFC
|--- G3D
|--- RIGHTBUS
|--- FSYS
|--- LCD0
|--- PERIR
|--- ISP
|--- CAM

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
[tjakobi: Reported debugfs error during booting and cw00.choi fix it.]
Reported-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

PM / devfreq: Add new passive governor

This patch adds the new passive governor for DEVFREQ framework. The following
governors are already present and used for DVFS (Dynamic Voltage and Frequency
Scaling) drivers. The following governors are independently used for one device
driver which don't give the influence to other device drviers and also don't
receive the effect from other device drivers.
- ondemand / performance / powersave / userspace

The passive governor depends on operation of parent driver with specific
governos extremely and is not able to decide the new frequency by oneself.
According to the decided new frequency of parent driver with governor,
the passive governor uses it to decide the appropriate frequency for own
device driver. The passive governor must need the following information
from device tree:
- the source clock and OPP tables
- the instance of parent device

For exameple,
there are one more devfreq device drivers which need to change their source
clock according to their utilization on runtime. But, they share the same
power line (e.g., regulator). So, specific device driver is operated as parent
with ondemand governor and then the rest device driver with passive governor
is influenced by parent device.

Suggested-by: Myungjoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
[tjakobi: Reported RCU locking issue and cw00.choi fix it]
Reported-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
[linux.amoon: Reported possible recursive locking and cw00.choi fix it]
Reported-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

PM / devfreq: exynos: Add generic exynos bus frequency driver

This patch adds the generic exynos bus frequency driver for AMBA AXI bus
of sub-blocks in exynos SoC with DEVFREQ framework. The Samsung Exynos SoC
have the common architecture for bus between DRAM and sub-blocks in SoC.
This driver can support the generic bus frequency driver for Exynos SoCs.

In devicetree, Each bus block has a bus clock, regulator, operation-point
and devfreq-event devices which measure the utilization of each bus block.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
[m.reichl and linux.amoon: Tested it on exynos4412-odroidu3 board]
Tested-by: Markus Reichl <m.reichl@fivetechno.de>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

PM / devfreq: Spelling s/frequnecy/frequency/

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / devfreq: event: Add devfreq_event class

This patch adds a new class in devfreq, devfreq_event, which provides
raw data (e.g., memory bus utilization, GPU utilization) for devfreq
governors.

- devfreq_event device : Provides raw data for a governor of a devfreq device
- devfreq device : Monitors device state and changes frequency/voltage
of the device using the raw data from its
devfreq_event device.

A devfreq device dertermines performance states (normally the frequency
and the voltage vlues) based on the results its designtated devfreq governor:
e.g., ondemand, performance, powersave.

In order to give such results required by a devfreq device, the devfreq
governor requires data that indicates the performance requirement given
to the devfreq device. The conventional (previous) implementatino of
devfreq subsystem requires a devfreq device driver to implement its own
mechanism to acquire performance requirement for its governor. However,
there had been issues with such requirements:

1. Although performance requirement of such devices is usually acquired
from common devices (PMU/PPMU), we do not have any abstract structure to
represent them properly.
2. Such performance requirement devices (PMU/PPMU) are actual hardware
pieces that may be represented by Device Tree directly while devfreq device
itself is a virtual entity that are not considered to be represented by
Device Tree according to Device Tree folks.

In order to address such issues, a devferq_event device (represented by
this patch) provides a template for device drivers representing
performance monitoring unit, which gives the basic or raw data for
preformance requirement, which in turn, is required by devfreq governors.

The following description explains the feature of two kind of devfreq class:
- devfreq class (existing)
: devfreq consumer device use raw data from devfreq_event device for
determining proper current system state and change voltage/frequency
dynamically using various governors.

- devfreq_event class (new)
: Provide measured raw data to devfreq device for governor

Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
[Commit message rewritten & conflict resolved by MyungJoo]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: tegra: add devfreq driver for Tegra Activity Monitor

The ACTMON block can monitor several counters, providing averaging and firing
interrupts based on watermarking configuration. This implementation monitors
the MCALL and MCCPU counters to choose an appropriate frequency for the
external memory clock.

This patch is based on work by Alex Frid <afrid@nvidia.com> and Mikko
Perttunen <mikko.perttunen@kapsi.fi>.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

rcu: Make SRCU optional by using CONFIG_SRCU

SRCU is not necessary to be compiled by default in all cases. For tinification
efforts not compiling SRCU unless necessary is desirable.

The current patch tries to make compiling SRCU optional by introducing a new
Kconfig option CONFIG_SRCU which is selected when any of the components making
use of SRCU are selected.

If we do not select CONFIG_SRCU, srcu.o will not be compiled at all.

text data bss dec hex filename
2007 0 0 2007 7d7 kernel/rcu/srcu.o

Size of arch/powerpc/boot/zImage changes from

text data bss dec hex filename
831552 64180 23944 919676 e087c arch/powerpc/boot/zImage : before
829504 64180 23952 917636 e0084 arch/powerpc/boot/zImage : after

so the savings are about ~2000 bytes.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]

PM / devfreq: exynos: Enable building exynos PPMU as module

Export symbols from the PPMU driver needed to build the exynos bus
driver as a module.

Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: Remove ARCH_HAS_OPP completely

The Kconfig symbol ARCH_HAS_OPP became redundant in v3.16: commit
049d595a4db3 ("PM / OPP: Make OPP invisible to users in Kconfig")
removed the only dependency that used it. Setting it had no effect
anymore.

So commit 78c5e0bb145d ("PM / OPP: Remove ARCH_HAS_OPP") removed it. For
some reason that commit did not remove all select statements for that
symbol. These statements are now useless. Remove one from devfreq too.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / OPP: Remove ARCH_HAS_OPP

Since the OPP layer is a kernel library which has been converted to be
directly selectable by its callers rather than user selectable and
requiring architectures to enable it explicitly the ARCH_HAS_OPP symbol
has become redundant and can be removed. Do so.

Signed-off-by: Mark Brown <broonie@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Nishanth Menon <nm@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / devfreq: remove checks for CONFIG_EXYNOS_ASV

Checks for CONFIG_EXYNOS_ASV were added in v3.3. But the related Kconfig
symbol has never been added to the tree. Remove these checks, as they
always evaluate to false.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
[Merge conflict resolved by MyungJoo]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: exynos5: Add CONFIG_PM_OPP dependency to fix probe fail

This patch add CONFIG_PM_OPP dependecy to exynos5_bus driver
to fix probe fail. If CONFIG_PM_OPP is disabled, dev_pm_opp_find_freq_floor()
will always return ERR_PTR(-EINVAL) error.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: exynos4: Add CONFIG_PM_OPP dependency to fix probe fail

This patch add CONFIG_PM_OPP dependecy to exynos4_bus driver
to fix probe fail as following log:

[ 3.721389] exynos4-busfreq busfreq.3: Fail to add opp entries.
[ 3.721697] exynos4-busfreq: probe of busfreq.3 failed with error -22

If CONFIG_PM_OPP is disabled, dev_pm_opp_find_freq_floor() in xxx_probe()
will always return -EINVAL error.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

PM / devfreq: Disable Exynos4 driver build on multiplatform

Exynos4 devfreq driver uses mach/map.h which is not available on
multiplatform. Hence disable build on multiplatform for now.
Without this patch we get the following build errors:
drivers/devfreq/exynos/exynos4_bus.h:15:22: fatal error: mach/map.h: No such file or directory

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / devfreq: fix typo "CPU_EXYNOS4.12" twice

Dependencies on CPU_EXYNOS4212 and CPU_EXYNOS4412 for the "ARM
Exynos4210/4212/4412 Memory Bus DEVFREQ Driver" were added in commit
7b4050381127ae11fcfc74a106d715a5fbbf888a ("PM/Devfreq: Add Exynos4-bus
device DVFS driver for Exynos4210/4212/4412."). The tree (at that time,
v3.3, and currently) makes clear that this should have been dependencies
on SOC_EXYNOS4212 and SOC_EXYNOS4412.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>

PM / devfreq: Add Exynos5-bus devfreq driver for Exynos5250

Exynos5-bus device devfreq driver monitors PPMU counters and
adjusts operating frequencies and voltages with OPP. ASV should
be used to provide appropriate voltages as per the speed group
of the SoC rather than using a constant 1.025V.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
[myungjoo.ham@samsung.com: minor style update]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Jonghwan Choi <jhbird.choi@samsung.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>

PM / devfreq: governors: add GPL module license and allow module build

Add GPL module license and remove the static build
restrictions for building governors. This allows governors now
to be loaded on a need basis and reloaded independently of kernel
build

Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
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

Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

Fix typo in various Kconfig file

Correct spelling typo in various Kconfig file.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412.

Exynos4-bus device devfreq driver add DVFS capability for
Exynos4210/4212/4412-Bus (memory). The driver monitors PPMU counters of memory
controllers and adjusts operating frequencies and voltages with OPP.
For Exynos4210, vdd_int is controlled. For exynos4412/4212, vdd_mif and
vdd_int are controlled.

Dependency (CONFIG_EXYNOS_ASV):
Exynos4 ASV driver has been posted in the mailing list; however, it
si not yet upstreamed. Although the current revision of Exynos4 ASV
patch does not contain "CONFIG_EXYNOS_ASV", we have added the symbol
to hide the dependent from compilers for now. As soon as Exynos4 ASV
drivers are merged, the #ifdef statement will be removed or the
name will be changed.

However, enabling ASV is essential in most Exynos4 chips to reduce
the power consumption of Exynos4210 because without ASV, this Devfreq
driver assumes the worst case scenario, which consumes more power.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

---
Changes from v1
- Support 4212 and 4412 as well as 4210.

PM / devfreq: correct Kconfig dependency

Devfreq does not depend on OPP. The dependency is removed.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM / devfreq: Add basic governors

Four cpufreq-like governors are provided as examples.

powersave: use the lowest frequency possible. The user (device) should
set the polling_ms as 0 because polling is useless for this governor.

performance: use the highest freqeuncy possible. The user (device)
should set the polling_ms as 0 because polling is useless for this
governor.

userspace: use the user specified frequency stored at
devfreq.user_set_freq. With sysfs support in the following patch, a user
may set the value with the sysfs interface.

simple_ondemand: simplified version of cpufreq's ondemand governor.

When a user updates OPP entries (enable/disable/add), OPP framework
automatically notifies devfreq to update operating frequency
accordingly. Thus, devfreq users (device drivers) do not need to update
devfreq manually with OPP entry updates or set polling_ms for powersave
, performance, userspace, or any other "static" governors.

Note that these are given only as basic examples for governors and any
devices with devfreq may implement their own governors with the drivers
and use them.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mike Turquette <mturquette@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM: Introduce devfreq: generic DVFS framework with device-specific OPPs

With OPPs, a device may have multiple operable frequency and voltage
sets. However, there can be multiple possible operable sets and a system
will need to choose one from them. In order to reduce the power
consumption (by reducing frequency and voltage) without affecting the
performance too much, a Dynamic Voltage and Frequency Scaling (DVFS)
scheme may be used.

This patch introduces the DVFS capability to non-CPU devices with OPPs.
DVFS is a techique whereby the frequency and supplied voltage of a
device is adjusted on-the-fly. DVFS usually sets the frequency as low
as possible with given conditions (such as QoS assurance) and adjusts
voltage according to the chosen frequency in order to reduce power
consumption and heat dissipation.

The generic DVFS for devices, devfreq, may appear quite similar with
/drivers/cpufreq. However, cpufreq does not allow to have multiple
devices registered and is not suitable to have multiple heterogenous
devices with different (but simple) governors.

Normally, DVFS mechanism controls frequency based on the demand for
the device, and then, chooses voltage based on the chosen frequency.
devfreq also controls the frequency based on the governor's frequency
recommendation and let OPP pick up the pair of frequency and voltage
based on the recommended frequency. Then, the chosen OPP is passed to
device driver's "target" callback.

When PM QoS is going to be used with the devfreq device, the device
driver should enable OPPs that are appropriate with the current PM QoS
requests. In order to do so, the device driver may call opp_enable and
opp_disable at the notifier callback of PM QoS so that PM QoS's
update_target() call enables the appropriate OPPs. Note that at least
one of OPPs should be enabled at any time; be careful when there is a
transition.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Mike Turquette <mturquette@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>