ARM: omap[34]: Thumb-2 compatibility fixes

This set of patches, along with some other patches under discussion on alkml, should enable omap3 and omap4 kernels to be built with CONFIG_THUMB2_KERNEL.

This patch set builds on recent cleanup done by the omap maintainers.

At least some of this code definitely works, most features have been tested successfully. Further testing, especially of Thumb-2 behaviour, is still welcome.

In particular, I still have no Ack/Tested-by on the following patches, so it would be great if anyone who has an opportunity to do a final review / re-test can do so.

* ARM: omap3: Convert END() to ENDPROC() for correct linkage with CONFIG_THUMB2_KERNEL
* ARM: omap3: Thumb-2 compatibility for sram34xx.S
* ARM: omap3: Thumb-2 compatibility for sleep34xx.S

Seems to work with CONFIG_SMP_ON_UP and CONFIG_THUMB2_KERNEL enabled on Beagle xM A2 and Panda A1.

Thanks also to Santosh Shilimkar and Kevin Hilman for their help with testing so far.

v3:
* make SMC instruction syntax more consistent
* remove do_wfi() in favour of the generic wfi() macro

v4:
* revert to the OMAP-specific do_wfi() implementation, pending discussion of how generic macros can/should be provided

v5:
* use ARM for low-level code in mach-omap2/*34xx.S, for correct interoperation with non-Thumb-capable firmware.

I've stripped the Acked/Tested-bys from the major patches to mach-omap2/*34xx.S, since the reversion to ARM constitutes a significant change -- I would be grateful if people could re- test / re-review if they have the chance.

For best future compatibility, I've left the changes which avoid architecturally deprecated features.

Details below.

Cheers,
Dave

The patches can be found, along with a buildable working tree, in the following repo:

git://git.linaro.org/people/dmart/linux-2.6-arm.git

* arm/omap-thumb2: has the patches proposed here
* arm/omap-thumb2+merged: additionally has some patches cherry- picked from other trees which are needed in order for the patches on arm/omap-thumb2 to work usefully.
* dirty/arm/omap-thumb2+merged: buildable test tree, which adds 2 local patches to work around a toolchain bug.

A working kernel config for this tree is here:
http://people.linaro.org/~dmart/arm_omap-thumb2+v2_config :

CONFIG_SMP_ON_UP=y
CONFIG_THUMB2_KERNEL=y
CONFIG_SERIAL_OMAP=y (to avoid garbage on xM; for Panda use console=ttyS2)

(The config is derived from the linaro omap config and so turns on loads of modules -- don't feel you have to build them all...)

Cherry-picked patches originated from Russell's devel tree and Tony Lindgren's omap-testing tree:

http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm.git devel

git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6.git omap-testing

This series also depends on one un-merged patch to generic-ise the wfi() macro:

git://git.linaro.org/people/dmart/linux-2.6-arm.git arm/wfi-macro

Dave Martin (5):
ARM: omap4: Provide do_wfi() for Thumb-2
ARM: omap4: Convert END() to ENDPROC() for correct linkage with
CONFIG_THUMB2_KERNEL
ARM: omap3: Remove hand-encoded SMC instructions
ARM: omap3: Thumb-2 compatibility for sram34xx.S
ARM: omap3: Thumb-2 compatibility for sleep34xx.S

 arch/arm/mach-omap2/include/mach/omap4-common.h |    4 ++
 arch/arm/mach-omap2/omap-headsmp.S              |    2 +-
 arch/arm/mach-omap2/omap44xx-smc.S              |    8 ++--
 arch/arm/mach-omap2/sleep34xx.S                 |   62 ++++++++++++++++++----
 arch/arm/mach-omap2/sram34xx.S                  |   36 ++++++++++---
 5 files changed, 87 insertions(+), 25 deletions(-)