xref: /linux/arch/powerpc/kernel/epapr_hcalls.S (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1/*
2 * Copyright (C) 2012 Freescale Semiconductor, Inc.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 */
9
10#include <linux/threads.h>
11#include <asm/epapr_hcalls.h>
12#include <asm/reg.h>
13#include <asm/page.h>
14#include <asm/cputable.h>
15#include <asm/thread_info.h>
16#include <asm/ppc_asm.h>
17#include <asm/asm-compat.h>
18#include <asm/asm-offsets.h>
19
20/* epapr_ev_idle() was derived from e500_idle() */
21_GLOBAL(epapr_ev_idle)
22	CURRENT_THREAD_INFO(r3, r1)
23	PPC_LL	r4, TI_LOCAL_FLAGS(r3)	/* set napping bit */
24	ori	r4, r4,_TLF_NAPPING	/* so when we take an exception */
25	PPC_STL	r4, TI_LOCAL_FLAGS(r3)	/* it will return to our caller */
26
27	wrteei	1
28
29idle_loop:
30	LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE))
31
32.global epapr_ev_idle_start
33epapr_ev_idle_start:
34	li	r3, -1
35	nop
36	nop
37	nop
38
39	/*
40	 * Guard against spurious wakeups from a hypervisor --
41	 * only interrupt will cause us to return to LR due to
42	 * _TLF_NAPPING.
43	 */
44	b	idle_loop
45
46/* Hypercall entry point. Will be patched with device tree instructions. */
47.global epapr_hypercall_start
48epapr_hypercall_start:
49	li	r3, -1
50	nop
51	nop
52	nop
53	blr
54