[PATCH V3 0/4] cpuidle : multiple drivers support

[Daniel Lezcano <daniel.lezcano@linaro.org>]

The discussion about having different cpus on the system with
different latencies bring us to a first attemp by adding a
pointer in the cpuidle_device to the states array.

But as Rafael suggested, it would make more sense to create a
driver per cpu [1].

This patch adds support for multiple cpuidle drivers.

It creates a per cpu cpuidle driver pointer.

In order to not break the different drivers, the function cpuidle_register_driver
assign for each cpu, the driver.

The multiple driver support is optional and if it is not set, the cpuide driver
core code remains the same (except some code reorganisation).

I did the following tests compiled, booted, tested without/with CONFIG_CPU_IDLE,
with/without CONFIG_CPU_IDLE_MULTIPLE_DRIVERS.

Tested on Core2 Duo T9500 with acpi_idle [and intel_idle]
Tested on ARM Dual Cortex-A9 U8500 (aka Snowball)

V1 tested on Tegra3 and Vexpress TC2

[1] http://www.spinics.net/lists/linux-acpi/msg37921.html

Changelog:

V2:
 * fixed sysfs output : /sys/devices/system/cpu/cpu[0-9]/driver/name
 * fixed ifdefs in driver.c
 * fixed register_driver function loop when unregistering
 * removed WARN under spinlock
 * fixed changelog for patch [2/4]
 * changed cpuidle_get_cpu_driver function parameter
 * removed cpuidle_for_each_driver function
 * replaced smp_processor_id() by get_cpu/put_cpu

V3:
 * refreshed patchset

Daniel Lezcano (4):
  cpuidle: move driver's refcount to cpuidle
  cpuidle: move driver checking within the lock section
  cpuidle: prepare the driver core to be multi drivers aware
  cpuidle: support multiple drivers

 drivers/cpuidle/Kconfig   |    9 ++
 drivers/cpuidle/cpuidle.c |   36 +++++---
 drivers/cpuidle/cpuidle.h |    4 +-
 drivers/cpuidle/driver.c  |  209 ++++++++++++++++++++++++++++++++++++++------
 drivers/cpuidle/sysfs.c   |  174 ++++++++++++++++++++++++++++++++++++--
 include/linux/cpuidle.h   |    8 ++-
 6 files changed, 388 insertions(+), 52 deletions(-)

-- 
1.7.5.4