[PATCH 00/25 v2] Re-jig cpu_suspend for a saner calling convention

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

Currently cpu_suspend is not like a normal C function - when it's called
it returns normally to a bunch of code which is not expected to return.
The return path is via code pointed to by 'r3'.

It also corrupts a bunch of registers in ways which make it non-compliant
with a C API.

If we do make this compliant as a normal C-like function, it eliminates
this register saving, and also allows us to make greater savings.  We
also swap 'lr' and 'r3', so cpu_suspend effectively only returns to
following code on resume - and r3 points to the suspend code.

So, this becomes:
static void soc_suspend(void)
{
        [soc specific preparation]

        cpu_suspend(0, PLAT_PHYS_OFFSET - PAGE_OFFSET,
                soc_suspend_arg, soc_finish_suspend);

        [soc specific cleanup ]
}

where soc_suspend_fn can be either assembly or C code - but must never
return.  (See separate patch posted on 13th June to allow it to return.)

This patch series also merges the call to cpu_init() into cpu_suspend(),
and makes cpu_init() call the per-CPU initialization function to ensure
that various registers are setup (eg, clock switching on StrongARM,
read-buffer enabled for userspace, etc.)  This allows some more custom
platform suspend code to be removed.

Lastly, I've made an attempt to (a) clean up OMAP3 suspend support a little
and (b) convert it to use cpu_suspend().  This works, but I've been unable
to test cpuidle as cpuidle doesn't want to enter any of the deeper sleep
states.

The only platform not converted to cpu_suspend() is the shmobile stuff,
which I've requested their assistance with.

This patch set also eliminates about 300 LOC from platform code.

Tested on Assabet (SA1100) and 3430LDP only.

 arch/arm/include/asm/system.h           |    2 +
 arch/arm/kernel/setup.c                 |   99 +++++++++++----------
 arch/arm/kernel/sleep.S                 |   71 ++++++---------
 arch/arm/mach-exynos4/pm.c              |    2 +-
 arch/arm/mach-exynos4/sleep.S           |   22 -----
 arch/arm/mach-omap2/pm34xx.c            |   39 ++-------
 arch/arm/mach-omap2/sleep34xx.S         |  147 ++----------------------------
 arch/arm/mach-pxa/include/mach/pm.h     |    4 +-
 arch/arm/mach-pxa/pm.c                  |    1 -
 arch/arm/mach-pxa/pxa25x.c              |    3 +-
 arch/arm/mach-pxa/pxa27x.c              |   11 ++-
 arch/arm/mach-pxa/pxa3xx.c              |   13 +++-
 arch/arm/mach-pxa/sleep.S               |   55 ++----------
 arch/arm/mach-pxa/zeus.c                |    3 +-
 arch/arm/mach-s3c2412/pm.c              |    4 +-
 arch/arm/mach-s3c2416/pm.c              |    4 +-
 arch/arm/mach-s3c64xx/pm.c              |    2 +-
 arch/arm/mach-s3c64xx/sleep.S           |   23 -----
 arch/arm/mach-s5pv210/pm.c              |    2 +-
 arch/arm/mach-s5pv210/sleep.S           |   21 -----
 arch/arm/mach-sa1100/pm.c               |    6 +-
 arch/arm/mach-sa1100/sleep.S            |   19 +----
 arch/arm/mm/proc-v7.S                   |   10 ++-
 arch/arm/plat-s3c24xx/sleep.S           |   25 -----
 arch/arm/plat-samsung/include/plat/pm.h |    5 +-
 arch/arm/plat-samsung/pm.c              |   10 +--
 26 files changed, 152 insertions(+), 451 deletions(-)