Excerpts from Christophe Leroy's message of January 26, 2021 12:48 am:

syscall_64.c will be reused almost as is for PPC32.

Rename it syscall.c

Could you rename it to interrupt.c instead? A system call is an 
interrupt, and the file now also has code to return from other
interrupts as well, and it matches the new asm/interrupt.h from
the interrupts series.

Thanks,
Nick