xref: /netbsd-src/sys/arch/x86/include/i8259.h (revision aad01611e7d49352752bfcd4a3f76ed8d8b2123e)
1 /*	$NetBSD: i8259.h,v 1.4 2003/08/07 16:30:32 agc Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * William Jolitz.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)icu.h	5.6 (Berkeley) 5/9/91
35  */
36 
37 #ifndef	_X86_I8259_H_
38 #define	_X86_I8259_H_
39 
40 #include <dev/isa/isareg.h>
41 
42 #ifndef	_LOCORE
43 
44 /*
45  * Interrupt "level" mechanism variables, masks, and macros
46  */
47 extern	unsigned i8259_imen;		/* interrupt mask enable */
48 extern unsigned i8259_setmask(unsigned);
49 
50 #define SET_ICUS()	(outb(IO_ICU1 + 1, imen), outb(IO_ICU2 + 1, imen >> 8))
51 
52 extern void i8259_default_setup(void);
53 extern void i8259_reinit(void);
54 
55 #endif /* !_LOCORE */
56 
57 /*
58  * Interrupt enable bits -- in order of priority
59  */
60 #define	IRQ_SLAVE	2
61 
62 /*
63  * Interrupt Control offset into Interrupt descriptor table (IDT)
64  */
65 #define	ICU_OFFSET	32		/* 0-31 are processor exceptions */
66 #define	ICU_LEN		16		/* 32-47 are ISA interrupts */
67 
68 
69 #define ICU_HARDWARE_MASK
70 
71 /*
72  * These macros are fairly self explanatory.  If ICU_SPECIAL_MASK_MODE is
73  * defined, we try to take advantage of the ICU's `special mask mode' by only
74  * EOIing the interrupts on return.  This avoids the requirement of masking and
75  * unmasking.  We can't do this without special mask mode, because the ICU
76  * would also hold interrupts that it thinks are of lower priority.
77  *
78  * Many machines do not support special mask mode, so by default we don't try
79  * to use it.
80  */
81 
82 #define	IRQ_BIT(num)	(1 << ((num) % 8))
83 #define	IRQ_BYTE(num)	((num) >> 3)
84 
85 #define i8259_late_ack(num)
86 
87 #ifdef ICU_SPECIAL_MASK_MODE
88 
89 #define	i8259_asm_ack1(num)
90 #define	i8259_asm_ack2(num) \
91 	movb	$(0x60|IRQ_SLAVE),%al	/* specific EOI for IRQ2 */	;\
92 	outb	%al,$IO_ICU1
93 #define	i8259_asm_mask(num)
94 #define	i8259_asm_unmask(num) \
95 	movb	$(0x60|(num%8)),%al	/* specific EOI */		;\
96 	outb	%al,$ICUADDR
97 
98 #else /* ICU_SPECIAL_MASK_MODE */
99 
100 #ifndef	AUTO_EOI_1
101 #define	i8259_asm_ack1(num) \
102 	movb	$(0x60|(num%8)),%al	/* specific EOI */		;\
103 	outb	%al,$IO_ICU1
104 #else
105 #define	i8259_asm_ack1(num)
106 #endif
107 
108 #ifndef AUTO_EOI_2
109 #define	i8259_asm_ack2(num) \
110 	movb	$(0x60|(num%8)),%al	/* specific EOI */		;\
111 	outb	%al,$IO_ICU2		/* do the second ICU first */	;\
112 	movb	$(0x60|IRQ_SLAVE),%al	/* specific EOI for IRQ2 */	;\
113 	outb	%al,$IO_ICU1
114 #else
115 #define	i8259_asm_ack2(num)
116 #endif
117 
118 #ifdef PIC_MASKDELAY
119 #define MASKDELAY	pushl %eax ; inb $0x84,%al ; popl %eax
120 #else
121 #define MASKDELAY
122 #endif
123 
124 #ifdef ICU_HARDWARE_MASK
125 
126 #define	i8259_asm_mask(num) \
127 	movb	CVAROFF(i8259_imen, IRQ_BYTE(num)),%al			;\
128 	orb	$IRQ_BIT(num),%al					;\
129 	movb	%al,CVAROFF(i8259_imen, IRQ_BYTE(num))			;\
130 	MASKDELAY							;\
131 	outb	%al,$(ICUADDR+1)
132 #define	i8259_asm_unmask(num) \
133 	movb	CVAROFF(i8259_imen, IRQ_BYTE(num)),%al			;\
134 	andb	$~IRQ_BIT(num),%al					;\
135 	movb	%al,CVAROFF(i8259_imen, IRQ_BYTE(num))			;\
136 	MASKDELAY							;\
137 	outb	%al,$(ICUADDR+1)
138 
139 #else /* ICU_HARDWARE_MASK */
140 
141 #define	i8259_asm_mask(num)
142 #define	i8259_asm_unmask(num)
143 
144 #endif /* ICU_HARDWARE_MASK */
145 #endif /* ICU_SPECIAL_MASK_MODE */
146 
147 #endif /* !_X86_I8259_H_ */
148