1/*	$OpenBSD: icu.s,v 1.36 2022/12/08 01:25:45 guenther Exp $	*/
2/*	$NetBSD: icu.s,v 1.45 1996/01/07 03:59:34 mycroft Exp $	*/
3
4/*-
5 * Copyright (c) 1993, 1994, 1995 Charles M. Hannum.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by Charles M. Hannum.
18 * 4. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33	.data
34	.globl	imen
35imen:
36	.long	0xffff		# interrupt mask enable (all off)
37
38	.text
39/*
40 * Process pending interrupts.
41 *
42 * Important registers:
43 *   ebx - cpl
44 *   esi - address to resume loop at
45 *   edi - scratch for Xsoftnet
46 */
47KIDTVEC(spllower)
48	pushl	%ebx
49	pushl	%esi
50	pushl	%edi
51	movl	CPL,%ebx		# save priority
52	movl	$1f,%esi		# address to resume loop at
531:	movl	%ebx,%eax		# get cpl
54	shrl	$4,%eax			# find its mask.
55	movl	iunmask(,%eax,4),%eax
56	cli
57	andl	CPUVAR(IPENDING),%eax	# any non-masked bits left?
58	jz	2f
59	sti
60	bsfl	%eax,%eax
61	btrl	%eax,CPUVAR(IPENDING)
62	jnc	1b
63	jmp	*Xrecurse(,%eax,4)
642:	movl	%ebx,CPL
65	sti
66	popl	%edi
67	popl	%esi
68	popl	%ebx
69	ret
70
71/*
72 * Handle return from interrupt after device handler finishes.
73 *
74 * Important registers:
75 *   ebx - cpl to restore
76 *   esi - address to resume loop at
77 *   edi - scratch for Xsoftnet
78 */
79KIDTVEC(doreti)
80	popl	%ebx			# get previous priority
81	movl	$1f,%esi		# address to resume loop at
821:	movl	%ebx,%eax
83	shrl	$4,%eax
84	movl	iunmask(,%eax,4),%eax
85	cli
86	andl	CPUVAR(IPENDING),%eax
87	jz	2f
88	sti
89	bsfl    %eax,%eax               # slow, but not worth optimizing
90	btrl    %eax,CPUVAR(IPENDING)
91	jnc     1b			# some intr cleared the in-memory bit
92	cli
93	jmp	*Xresume(,%eax,4)
942:	/* Check for ASTs on exit to user mode. */
95	CHECK_ASTPENDING(%ecx)
96	movl	%ebx,CPL
97	je	3f
98	testb   $SEL_RPL,TF_CS(%esp)
99	jz	3f
1004:	CLEAR_ASTPENDING(%ecx)
101	sti
102	pushl	%esp
103	call	ast
104	addl	$4,%esp
105	cli
106	jmp	2b
1073:
108#ifdef DIAGNOSTIC
109	movl	$0xf9,%esi
110#endif
111	INTRFASTEXIT
112
113
114/*
115 * Soft interrupt handlers
116 */
117
118KIDTVEC(softtty)
119	movl	$IPL_SOFTTTY,%eax
120	movl	%eax,CPL
121	sti
122	pushl	$I386_SOFTINTR_SOFTTTY
123	call	softintr_dispatch
124	addl	$4,%esp
125	jmp	*%esi
126
127KIDTVEC(softnet)
128	movl	$IPL_SOFTNET,%eax
129	movl	%eax,CPL
130	sti
131	pushl	$I386_SOFTINTR_SOFTNET
132	call	softintr_dispatch
133	addl	$4,%esp
134	jmp	*%esi
135#undef DONETISR
136
137KIDTVEC(softclock)
138	movl	$IPL_SOFTCLOCK,%eax
139	movl	%eax,CPL
140	sti
141	pushl	$I386_SOFTINTR_SOFTCLOCK
142	call	softintr_dispatch
143	addl	$4,%esp
144	jmp	*%esi
145
146