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 64 bits e500 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.macro BOOK3E_IDLE name loop
20_GLOBAL(\name)
21	/* Save LR for later */
22	mflr	r0
23	std	r0,16(r1)
24
25	/* Hard disable interrupts */
26	wrteei	0
27
28	/* Now check if an interrupt came in while we were soft disabled
29	 * since we may otherwise lose it (doorbells etc...).
30	 */
31	lbz	r3,PACAIRQHAPPENED(r13)
32	cmpwi	cr0,r3,0
33	bne	2f
34
35	/* Now we are going to mark ourselves as soft and hard enabled in
36	 * order to be able to take interrupts while asleep. We inform lockdep
37	 * of that. We don't actually turn interrupts on just yet tho.
38	 */
39#ifdef CONFIG_TRACE_IRQFLAGS
40	stdu    r1,-128(r1)
41	bl	trace_hardirqs_on
42	addi    r1,r1,128
43#endif
44	li	r0,IRQS_ENABLED
45	stb	r0,PACAIRQSOFTMASK(r13)
46
47	/* Interrupts will make use return to LR, so get something we want
48	 * in there
49	 */
50	bl	1f
51
52	/* And return (interrupts are on) */
53	ld	r0,16(r1)
54	mtlr	r0
55	blr
56
571:	/* Let's set the _TLF_NAPPING flag so interrupts make us return
58	 * to the right spot
59	*/
60	ld	r11, PACACURRENT(r13)
61	ld	r10,TI_LOCAL_FLAGS(r11)
62	ori	r10,r10,_TLF_NAPPING
63	std	r10,TI_LOCAL_FLAGS(r11)
64
65	/* We can now re-enable hard interrupts and go to sleep */
66	wrteei	1
67	\loop
68
692:
70	lbz	r10,PACAIRQHAPPENED(r13)
71	ori	r10,r10,PACA_IRQ_HARD_DIS
72	stb	r10,PACAIRQHAPPENED(r13)
73	blr
74.endm
75
76.macro BOOK3E_IDLE_LOOP
771:
78	PPC_WAIT_v203
79	b	1b
80.endm
81
82/* epapr_ev_idle_start below is patched with the proper hcall
83   opcodes during kernel initialization */
84.macro EPAPR_EV_IDLE_LOOP
85idle_loop:
86	LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE))
87
88.global epapr_ev_idle_start
89epapr_ev_idle_start:
90	li      r3, -1
91	nop
92	nop
93	nop
94	b       idle_loop
95.endm
96
97BOOK3E_IDLE epapr_ev_idle EPAPR_EV_IDLE_LOOP
98
99BOOK3E_IDLE e500_idle BOOK3E_IDLE_LOOP
100