does the SAVE_ALL nesting in kernel?

[zhuzhenhua <zzh.hust@xxxxxxxxx>]

hello, all
            i
have a mips board,  and the SDRAM speed(bus clock) is not too fast.
             so i want change 
the SAVE_ALL and RESTORE_ALL to use internal-ram(high speed).
            i
just wonder whether the SAVE_ALL netsting in kernel  for mips arch?
            if not, i think  maybe
1k byte for SAVE_ALL is enough( 32regs X4, and some cp0_regs).
            but if  the SAVE_ALL nesting, maybe i need to keep a stack in internal-ram.
            thanks for any hints．

Best Regards

--
zzh