__set_cpsr_c
__set_cpsr_c(PSR_I, 0);
static __inline u_int32_t __set_cpsr_c(u_int bic, u_int eor);
(__set_cpsr_c((mask) & (PSR_I | PSR_F), \
(__set_cpsr_c((mask) & (PSR_I | PSR_F), 0))
(__set_cpsr_c((PSR_I | PSR_F), (old_cpsr) & (PSR_I | PSR_F)))
#define MCOUNT_ENTER s = __set_cpsr_c(0x0080, 0x0080); /* kill IRQ */
#define MCOUNT_EXIT __set_cpsr_c(0xffffffff, s); /* restore old value */