ints.c

  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 */
 33asmlinkage void system_call(void);
 34asmlinkage void buserr(void);
 35asmlinkage void trap(void);
 36asmlinkage void trap3(void);
 37asmlinkage void trap4(void);
 38asmlinkage void trap5(void);
 39asmlinkage void trap6(void);
 40asmlinkage void trap7(void);
 41asmlinkage void trap8(void);
 42asmlinkage void trap9(void);
 43asmlinkage void trap10(void);
 44asmlinkage void trap11(void);
 45asmlinkage void trap12(void);
 46asmlinkage void trap13(void);
 47asmlinkage void trap14(void);
 48asmlinkage void trap15(void);
 49asmlinkage void trap33(void);
 50asmlinkage void trap34(void);
 51asmlinkage void trap35(void);
 52asmlinkage void trap36(void);
 53asmlinkage void trap37(void);
 54asmlinkage void trap38(void);
 55asmlinkage void trap39(void);
 56asmlinkage void trap40(void);
 57asmlinkage void trap41(void);
 58asmlinkage void trap42(void);
 59asmlinkage void trap43(void);
 60asmlinkage void trap44(void);
 61asmlinkage void trap45(void);
 62asmlinkage void trap46(void);
 63asmlinkage void trap47(void);
 64asmlinkage irqreturn_t bad_interrupt(int, void *);
 65asmlinkage irqreturn_t inthandler(void);
 66asmlinkage irqreturn_t inthandler1(void);
 67asmlinkage irqreturn_t inthandler2(void);
 68asmlinkage irqreturn_t inthandler3(void);
 69asmlinkage irqreturn_t inthandler4(void);
 70asmlinkage irqreturn_t inthandler5(void);
 71asmlinkage irqreturn_t inthandler6(void);
 72asmlinkage 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 */
 80asmlinkage 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
136static void intc_irq_unmask(struct irq_data *d)
137{
138	IMR &= ~(1 << d->irq);
139}
140
141static void intc_irq_mask(struct irq_data *d)
142{
143	IMR |= (1 << d->irq);
144}
145
146static 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 */
156void __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
175void __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