1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright 2010 IBM Corp, Benjamin Herrenschmidt <benh@kernel.crashing.org>
4 *
5 * Generic idle routine for Book3E processors
6 */
7
8#include <linux/threads.h>
9#include <asm/reg.h>
10#include <asm/ppc_asm.h>
11#include <asm/asm-offsets.h>
12#include <asm/ppc-opcode.h>
13#include <asm/processor.h>
14#include <asm/thread_info.h>
15#include <asm/epapr_hcalls.h>
16#include <asm/hw_irq.h>
17
18/* 64-bit version only for now */
19#ifdef CONFIG_PPC64
20
21.macro BOOK3E_IDLE name loop
22_GLOBAL(\name)
23	/* Save LR for later */
24	mflr	r0
25	std	r0,16(r1)
26
27	/* Hard disable interrupts */
28	wrteei	0
29
30	/* Now check if an interrupt came in while we were soft disabled
31	 * since we may otherwise lose it (doorbells etc...).
32	 */
33	lbz	r3,PACAIRQHAPPENED(r13)
34	cmpwi	cr0,r3,0
35	bne	2f
36
37	/* Now we are going to mark ourselves as soft and hard enabled in
38	 * order to be able to take interrupts while asleep. We inform lockdep
39	 * of that. We don't actually turn interrupts on just yet tho.
40	 */
41#ifdef CONFIG_TRACE_IRQFLAGS
42	stdu    r1,-128(r1)
43	bl	trace_hardirqs_on
44	addi    r1,r1,128
45#endif
46	li	r0,IRQS_ENABLED
47	stb	r0,PACAIRQSOFTMASK(r13)
48
49	/* Interrupts will make use return to LR, so get something we want
50	 * in there
51	 */
52	bl	1f
53
54	/* And return (interrupts are on) */
55	ld	r0,16(r1)
56	mtlr	r0
57	blr
58
591:	/* Let's set the _TLF_NAPPING flag so interrupts make us return
60	 * to the right spot
61	*/
62	ld	r11, PACACURRENT(r13)
63	ld	r10,TI_LOCAL_FLAGS(r11)
64	ori	r10,r10,_TLF_NAPPING
65	std	r10,TI_LOCAL_FLAGS(r11)
66
67	/* We can now re-enable hard interrupts and go to sleep */
68	wrteei	1
69	\loop
70
712:
72	lbz	r10,PACAIRQHAPPENED(r13)
73	ori	r10,r10,PACA_IRQ_HARD_DIS
74	stb	r10,PACAIRQHAPPENED(r13)
75	blr
76.endm
77
78.macro BOOK3E_IDLE_LOOP
791:
80	PPC_WAIT(0)
81	b	1b
82.endm
83
84/* epapr_ev_idle_start below is patched with the proper hcall
85   opcodes during kernel initialization */
86.macro EPAPR_EV_IDLE_LOOP
87idle_loop:
88	LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE))
89
90.global epapr_ev_idle_start
91epapr_ev_idle_start:
92	li      r3, -1
93	nop
94	nop
95	nop
96	b       idle_loop
97.endm
98
99BOOK3E_IDLE epapr_ev_idle EPAPR_EV_IDLE_LOOP
100
101BOOK3E_IDLE book3e_idle BOOK3E_IDLE_LOOP
102
103#endif /* CONFIG_PPC64 */
104