1/*
 2 * Copyright 2010 IBM Corp, Benjamin Herrenschmidt <benh@kernel.crashing.org>
 3 *
 4 * Generic idle routine for Book3E processors
 5 *
 6 * This program is free software; you can redistribute it and/or
 7 * modify it under the terms of the GNU General Public License
 8 * as published by the Free Software Foundation; either version
 9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/threads.h>
13#include <asm/reg.h>
14#include <asm/ppc_asm.h>
15#include <asm/asm-offsets.h>
16#include <asm/ppc-opcode.h>
17#include <asm/processor.h>
18#include <asm/thread_info.h>
19
20/* 64-bit version only for now */
21#ifdef CONFIG_PPC64
22
23_GLOBAL(book3e_idle)
24	/* Save LR for later */
25	mflr	r0
26	std	r0,16(r1)
27
28	/* Hard disable interrupts */
29	wrteei	0
30
31	/* Now check if an interrupt came in while we were soft disabled
32	 * since we may otherwise lose it (doorbells etc...).
33	 */
34	lbz	r3,PACAIRQHAPPENED(r13)
35	cmpwi	cr0,r3,0
36	bnelr
37
38	/* Now we are going to mark ourselves as soft and hard enabled in
39	 * order to be able to take interrupts while asleep. We inform lockdep
40	 * of that. We don't actually turn interrupts on just yet tho.
41	 */
42#ifdef CONFIG_TRACE_IRQFLAGS
43	stdu    r1,-128(r1)
44	bl	.trace_hardirqs_on
45	addi    r1,r1,128
46#endif
47	li	r0,1
48	stb	r0,PACASOFTIRQEN(r13)
49	
50	/* Interrupts will make use return to LR, so get something we want
51	 * in there
52	 */
53	bl	1f
54
55	/* And return (interrupts are on) */
56	ld	r0,16(r1)
57	mtlr	r0
58	blr
59
601:	/* Let's set the _TLF_NAPPING flag so interrupts make us return
61	 * to the right spot
62	*/
63	clrrdi	r11,r1,THREAD_SHIFT
64	ld	r10,TI_LOCAL_FLAGS(r11)
65	ori	r10,r10,_TLF_NAPPING
66	std	r10,TI_LOCAL_FLAGS(r11)
67
68	/* We can now re-enable hard interrupts and go to sleep */
69	wrteei	1
701:	PPC_WAIT(0)
71	b	1b
72
73#endif /* CONFIG_PPC64 */