summaryrefslogtreecommitdiff
path: root/sys/arch/arm/cortex/gic_splfuncs_armv8.S
blob: ac2a987da59310a35a5fcd05f53ffd2b0aa71fb7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/* $NetBSD: gic_splfuncs_armv8.S,v 1.3 2021/10/31 15:32:14 jmcneill Exp $ */

/*-
 * Copyright (c) 2021 Jared McNeill <jmcneill@invisible.ca>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <machine/asm.h>
#include "assym.h"

RCSID("$NetBSD: gic_splfuncs_armv8.S,v 1.3 2021/10/31 15:32:14 jmcneill Exp $")

#ifdef __HAVE_PREEMPTION
#define	DISABLE_PREEMPTION			\
	ldr	w1, [x3, #L_NOPREEMPT];		\
	add	w1, w1, #1;			\
	str	w1, [x3, #L_NOPREEMPT]
#define	ENABLE_PREEMPTION			\
	ldr	w1, [x3, #L_NOPREEMPT];		\
	sub	w1, w1, #1;			\
	str	w1, [x3, #L_NOPREEMPT]
#else
#define	DISABLE_PREEMPTION
#define	ENABLE_PREEMPTION
#endif

/*
 * int
 * gic_splraise(int newipl)
 *
 *	w0 = newipl
 */
	.align 7        /* cacheline-aligned */
ENTRY_NP(gic_splraise)
	/* Save curlwp in x3, curcpu in x1 */
	mrs	x3, tpidr_el1			/* get curlwp */
	DISABLE_PREEMPTION
	ldr	x1, [x3, #L_CPU]		/* get curcpu */

	/* If newipl > cpl, update cpl */
	ldr	w2, [x1, #CI_CPL]
	cmp	w0, w2
	b.le	.Lnoraise
	str	w0, [x1, #CI_CPL]

.Lnoraise:
	ENABLE_PREEMPTION
	mov	w0, w2				/* return oldipl */
	ret
END(gic_splraise)


/*
 * void
 * gic_splx(int newipl)
 *
 *	w0 = newipl
 */
	.align 7        /* cacheline-aligned */
ENTRY_NP(gic_splx)
	/* Save curlwp in x3, curcpu in x1 */
	mrs	x3, tpidr_el1			/* get curlwp */
	DISABLE_PREEMPTION
	ldr	x1, [x3, #L_CPU]		/* get curcpu */

.Lagain:
	/* If newipl >= cpl, just return */
	ldr	w2, [x1, #CI_CPL]
	cmp	w0, w2
	b.hs	.Ldone

	/* Slow path if ci_intr_depth != 0 */
	ldr	w2, [x1, #CI_INTR_DEPTH]
	cbnz	w2, .Lslow

	/* Save newipl and restart address in cpu info */
	str	w0, [x1, #CI_SPLX_SAVEDIPL]
	adr	x2, .Lrestart
	str	x2, [x1, #CI_SPLX_RESTART]

	/* Slow path if hwpl > newipl */
	ldr	w2, [x1, #CI_HWPL]
	cmp	w2, w0
	b.hi	.Lrestore

	/* Update cpl */
	str	w0, [x1, #CI_CPL]

	/* Clear saved restart address from cpu info */
	str	xzr, [x1, #CI_SPLX_RESTART]

	/* Check for pending softints */
	ldr	w2, [x1, #CI_SOFTINTS]
	lsr	w2, w2, w0
	cbnz	w2, _C_LABEL(dosoftints)

.Ldone:
	ENABLE_PREEMPTION
	ret

.Lrestart:
	/* Reload registers */
	mrs	x3, tpidr_el1			/* get curlwp */
	ldr	x1, [x3, #L_CPU]		/* get curcpu */
	ldr	w0, [x1, #CI_SPLX_SAVEDIPL]	/* get newipl */
	b	.Lagain
	
.Lrestore:
	/* Clear saved restart address from cpu info */
	str	xzr, [x1, #CI_SPLX_RESTART]

.Lslow:
	ENABLE_PREEMPTION
	/* Jump to slow path */
	b	_C_LABEL(Xgic_splx)
END(gic_splx)