>> The platform code can do this itself.  Our (internal) platform lowers
>> the spl to the appropriate spl before calling the isr.  Handling
>> SR_INT_IE is easy enough, but it would be a cleaner interface.
>
> This discussion reminds me a related issue.
>
> Why do syscall() entry and trap() entry of mips/mips/trap.c disable
> software interrupts at the first of the function?
> As far as I know, other platform don't do this.

It's a mistake, or an artifact, which was dragged from the old times
of NetBSD/mips when syscall() was the part of trap().  The code path
of syscall() must be re-furblished. 

Tohru Nishimura