The first time interrupt nesting occurs between REE and TEE,
CURRENT_REGS needs to be set.
If TEE nesting REE breaks, then EXC_RETURN.S=0,EXC_RETURN.ES=1;
Conversely, EXC_RETURN.S=1,EXC_RETURN.ES=0;
Interrupt nesting between TEE and REE can be determined based
on the S and ES bits of EXC_RETURN.
Only once nesting between TEE and REE is supported, and cyclic
nesting between TEE and REE is not supported.
Signed-off-by: wangming9 <wangming9@xiaomi.com>
8d21bbf3be