[PATCH] ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+

[Andrew Lunn]

On Tue, Jul 01, 2014 at 04:58:24PM +0100, Russell King wrote:
> ARMv6 and greater introduced a new instruction ("bx") which can be used
> to return from function calls.  Recent CPUs perform better when the
> "bx lr" instruction is used rather than the "mov pc, lr" instruction,
> and this sequence is strongly recommended to be used by the ARM
> architecture manual (section A.4.1.1).
> 
> We provide a new macro "ret" with all its variants for the condition
> code which will resolve to the appropriate instruction.
> 
> Rather than doing this piecemeal, and miss some instances, change all
> the "mov pc" instances to use the new macro, with the exception of
> the "movs" instruction and the kprobes code.  This allows us to detect
> the "mov pc, lr" case and fix it up - and also gives us the possibility
> of deploying this for other registers depending on the CPU selection.
> 
> Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>

Hi Russell

Boot tested on kirkwood.

Tested-by: Andrew Lunn <andrew at lunn.ch>

	   Andrew