This patch reworks the sh3/sh4/sh4a register saving code in
the following ways:
- break out prepare_stack_save_dsp() from handle_exception()
- break out save_regs() from handle_exception()
- the register saving order is unchanged
- align new functions to fit in cache lines
- separate exception code from interrupt code
- keep main code flow in a single cache line per exception vector
- use bsr/rts for regular functions (save pr first)
- keep data in one shared cache line (exception_data)
- document the functions
- tie in the hp6xx code
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>