1/*
2 *  This file contains the power_save function for 970-family CPUs.
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/processor.h>
12#include <asm/page.h>
13#include <asm/cputable.h>
14#include <asm/thread_info.h>
15#include <asm/ppc_asm.h>
16#include <asm/asm-offsets.h>
17
18#undef DEBUG
19
20	.text
21
22_GLOBAL(power4_idle)
23BEGIN_FTR_SECTION
24	blr
25END_FTR_SECTION_IFCLR(CPU_FTR_CAN_NAP)
26	/* Now check if user or arch enabled NAP mode */
27	LOAD_REG_ADDRBASE(r3,powersave_nap)
28	lwz	r4,ADDROFF(powersave_nap)(r3)
29	cmpwi	0,r4,0
30	beqlr
31
32	/* Go to NAP now */
33	mfmsr	r7
34	rldicl	r0,r7,48,1
35	rotldi	r0,r0,16
36	mtmsrd	r0,1			/* hard-disable interrupts */
37	li	r0,1
38	stb	r0,PACASOFTIRQEN(r13)	/* we'll hard-enable shortly */
39	stb	r0,PACAHARDIRQEN(r13)
40BEGIN_FTR_SECTION
41	DSSALL
42	sync
43END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
44	clrrdi	r9,r1,THREAD_SHIFT	/* current thread_info */
45	ld	r8,TI_LOCAL_FLAGS(r9)	/* set napping bit */
46	ori	r8,r8,_TLF_NAPPING	/* so when we take an exception */
47	std	r8,TI_LOCAL_FLAGS(r9)	/* it will return to our caller */
48	ori	r7,r7,MSR_EE
49	oris	r7,r7,MSR_POW@h
501:	sync
51	isync
52	mtmsrd	r7
53	isync
54	b	1b
55
56