xref: /linux/arch/powerpc/kernel/epapr_hcalls.S (revision a06c3fad49a50d5d5eb078f93e70f4d3eca5d5a5)
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright (C) 2012 Freescale Semiconductor, Inc.
4 */
5
6#include <linux/export.h>
7#include <linux/threads.h>
8#include <asm/epapr_hcalls.h>
9#include <asm/reg.h>
10#include <asm/page.h>
11#include <asm/cputable.h>
12#include <asm/thread_info.h>
13#include <asm/ppc_asm.h>
14#include <asm/asm-compat.h>
15#include <asm/asm-offsets.h>
16
17#ifndef CONFIG_PPC64
18/* epapr_ev_idle() was derived from e500_idle() */
19_GLOBAL(epapr_ev_idle)
20	PPC_LL	r4, TI_LOCAL_FLAGS(r2)	/* set napping bit */
21	ori	r4, r4,_TLF_NAPPING	/* so when we take an exception */
22	PPC_STL	r4, TI_LOCAL_FLAGS(r2)	/* it will return to our caller */
23
24#ifdef CONFIG_BOOKE
25	wrteei	1
26#else
27	mfmsr	r4
28	ori	r4, r4, MSR_EE
29	mtmsr	r4
30#endif
31
32idle_loop:
33	LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE))
34
35.global epapr_ev_idle_start
36epapr_ev_idle_start:
37	li	r3, -1
38	nop
39	nop
40	nop
41
42	/*
43	 * Guard against spurious wakeups from a hypervisor --
44	 * only interrupt will cause us to return to LR due to
45	 * _TLF_NAPPING.
46	 */
47	b	idle_loop
48#endif
49
50/* Hypercall entry point. Will be patched with device tree instructions. */
51.global epapr_hypercall_start
52epapr_hypercall_start:
53	li	r3, -1
54	nop
55	nop
56	nop
57	blr
58EXPORT_SYMBOL(epapr_hypercall_start)
59