xref: /linux/arch/m68k/68000/ints.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
1 /*
2  * ints.c - Generic interrupt controller support
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file COPYING in the main directory of this archive
6  * for more details.
7  *
8  * Copyright 1996 Roman Zippel
9  * Copyright 1999 D. Jeff Dionne <jeff@rt-control.com>
10  */
11 
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/cpu.h>
18 #include <asm/traps.h>
19 #include <asm/io.h>
20 #include <asm/machdep.h>
21 
22 #if defined(CONFIG_M68EZ328)
23 #include <asm/MC68EZ328.h>
24 #elif defined(CONFIG_M68VZ328)
25 #include <asm/MC68VZ328.h>
26 #else
27 #include <asm/MC68328.h>
28 #endif
29 
30 #include "ints.h"
31 
32 /* assembler routines */
33 asmlinkage void system_call(void);
34 asmlinkage void buserr(void);
35 asmlinkage void trap(void);
36 asmlinkage void trap3(void);
37 asmlinkage void trap4(void);
38 asmlinkage void trap5(void);
39 asmlinkage void trap6(void);
40 asmlinkage void trap7(void);
41 asmlinkage void trap8(void);
42 asmlinkage void trap9(void);
43 asmlinkage void trap10(void);
44 asmlinkage void trap11(void);
45 asmlinkage void trap12(void);
46 asmlinkage void trap13(void);
47 asmlinkage void trap14(void);
48 asmlinkage void trap15(void);
49 asmlinkage void trap33(void);
50 asmlinkage void trap34(void);
51 asmlinkage void trap35(void);
52 asmlinkage void trap36(void);
53 asmlinkage void trap37(void);
54 asmlinkage void trap38(void);
55 asmlinkage void trap39(void);
56 asmlinkage void trap40(void);
57 asmlinkage void trap41(void);
58 asmlinkage void trap42(void);
59 asmlinkage void trap43(void);
60 asmlinkage void trap44(void);
61 asmlinkage void trap45(void);
62 asmlinkage void trap46(void);
63 asmlinkage void trap47(void);
64 asmlinkage irqreturn_t bad_interrupt(int, void *);
65 asmlinkage irqreturn_t inthandler(void);
66 asmlinkage irqreturn_t inthandler1(void);
67 asmlinkage irqreturn_t inthandler2(void);
68 asmlinkage irqreturn_t inthandler3(void);
69 asmlinkage irqreturn_t inthandler4(void);
70 asmlinkage irqreturn_t inthandler5(void);
71 asmlinkage irqreturn_t inthandler6(void);
72 asmlinkage irqreturn_t inthandler7(void);
73 
74 /* The 68k family did not have a good way to determine the source
75  * of interrupts until later in the family.  The EC000 core does
76  * not provide the vector number on the stack, we vector everything
77  * into one vector and look in the blasted mask register...
78  * This code is designed to be fast, almost constant time, not clean!
79  */
80 asmlinkage void process_int(int vec, struct pt_regs *fp)
81 {
82 	int irq;
83 	int mask;
84 
85 	unsigned long pend = ISR;
86 
87 	while (pend) {
88 		if (pend & 0x0000ffff) {
89 			if (pend & 0x000000ff) {
90 				if (pend & 0x0000000f) {
91 					mask = 0x00000001;
92 					irq = 0;
93 				} else {
94 					mask = 0x00000010;
95 					irq = 4;
96 				}
97 			} else {
98 				if (pend & 0x00000f00) {
99 					mask = 0x00000100;
100 					irq = 8;
101 				} else {
102 					mask = 0x00001000;
103 					irq = 12;
104 				}
105 			}
106 		} else {
107 			if (pend & 0x00ff0000) {
108 				if (pend & 0x000f0000) {
109 					mask = 0x00010000;
110 					irq = 16;
111 				} else {
112 					mask = 0x00100000;
113 					irq = 20;
114 				}
115 			} else {
116 				if (pend & 0x0f000000) {
117 					mask = 0x01000000;
118 					irq = 24;
119 				} else {
120 					mask = 0x10000000;
121 					irq = 28;
122 				}
123 			}
124 		}
125 
126 		while (! (mask & pend)) {
127 			mask <<=1;
128 			irq++;
129 		}
130 
131 		do_IRQ(irq, fp);
132 		pend &= ~mask;
133 	}
134 }
135 
136 static void intc_irq_unmask(struct irq_data *d)
137 {
138 	IMR &= ~(1 << d->irq);
139 }
140 
141 static void intc_irq_mask(struct irq_data *d)
142 {
143 	IMR |= (1 << d->irq);
144 }
145 
146 static struct irq_chip intc_irq_chip = {
147 	.name		= "M68K-INTC",
148 	.irq_mask	= intc_irq_mask,
149 	.irq_unmask	= intc_irq_unmask,
150 };
151 
152 /*
153  * This function should be called during kernel startup to initialize
154  * the machine vector table.
155  */
156 void __init trap_init(void)
157 {
158 	int i;
159 
160 	/* set up the vectors */
161 	for (i = 72; i < 256; ++i)
162 		_ramvec[i] = (e_vector) bad_interrupt;
163 
164 	_ramvec[32] = system_call;
165 
166 	_ramvec[65] = (e_vector) inthandler1;
167 	_ramvec[66] = (e_vector) inthandler2;
168 	_ramvec[67] = (e_vector) inthandler3;
169 	_ramvec[68] = (e_vector) inthandler4;
170 	_ramvec[69] = (e_vector) inthandler5;
171 	_ramvec[70] = (e_vector) inthandler6;
172 	_ramvec[71] = (e_vector) inthandler7;
173 }
174 
175 void __init init_IRQ(void)
176 {
177 	int i;
178 
179 	IVR = 0x40; /* Set DragonBall IVR (interrupt base) to 64 */
180 
181 	/* turn off all interrupts */
182 	IMR = ~0;
183 
184 	for (i = 0; (i < NR_IRQS); i++) {
185 		irq_set_chip(i, &intc_irq_chip);
186 		irq_set_handler(i, handle_level_irq);
187 	}
188 }
189 
190