ARC: add some more comments to ret_from_fork

	; put last task in scheduler queue

	bl   @schedule_tail

	; If kernel thread, jump to its entry-point

	ld   r9, [sp, PT_status32]

	brne r9, 0, 1f

	jl.d [r14]

	mov  r0, r13		; arg to payload

	jl.d [r14]		; kernel thread entry point

	mov  r0, r13		; (see PF_KTHREAD block in copy_thread)

1:

	; special case of kernel_thread entry point returning back due to

	; kernel_execve() - pretend return from syscall to ret to userland

	; Return to user space

	; 1. Any forked task (Reach here via BRne above)

	; 2. First ever init task (Reach here via return from JL above)

	;    This is the historic "kernel_execve" use-case, to return to init

	;    user mode, in a round about way since that is always done from

	;    a kernel thread which is executed via JL above but always returns

	;    out whenever kernel_execve (now inline do_fork()) is involved

	b    ret_from_exception

END(ret_from_fork)