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/*
* IRQ vector handles
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1995, 1996, 1997, 2003 by Ralf Baechle
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <asm/i8259.h>
#include <asm/irq_cpu.h>
#include <asm/gt64120.h>
#include <cobalt.h>
/*
* We have two types of interrupts that we handle, ones that come in through
* the CPU interrupt lines, and ones that come in on the via chip. The CPU
* mappings are:
*
* 16 - Software interrupt 0 (unused) IE_SW0
* 17 - Software interrupt 1 (unused) IE_SW1
* 18 - Galileo chip (timer) IE_IRQ0
* 19 - Tulip 0 + NCR SCSI IE_IRQ1
* 20 - Tulip 1 IE_IRQ2
* 21 - 16550 UART IE_IRQ3
* 22 - VIA southbridge PIC IE_IRQ4
* 23 - unused IE_IRQ5
*
* The VIA chip is a master/slave 8259 setup and has the following interrupts:
*
* 8 - RTC
* 9 - PCI
* 14 - IDE0
* 15 - IDE1
*/
static inline void galileo_irq(void)
{
unsigned int mask, pending, devfn;
mask = GT_READ(GT_INTRMASK_OFS);
pending = GT_READ(GT_INTRCAUSE_OFS) & mask;
if (pending & GT_INTR_T0EXP_MSK) {
GT_WRITE(GT_INTRCAUSE_OFS, ~GT_INTR_T0EXP_MSK);
do_IRQ(COBALT_GALILEO_IRQ);
} else if (pending & GT_INTR_RETRYCTR0_MSK) {
devfn = GT_READ(GT_PCI0_CFGADDR_OFS) >> 8;
GT_WRITE(GT_INTRCAUSE_OFS, ~GT_INTR_RETRYCTR0_MSK);
printk(KERN_WARNING
"Galileo: PCI retry count exceeded (%02x.%u)\n",
PCI_SLOT(devfn), PCI_FUNC(devfn));
} else {
GT_WRITE(GT_INTRMASK_OFS, mask & ~pending);
printk(KERN_WARNING
"Galileo: masking unexpected interrupt %08x\n", pending);
}
}
static inline void via_pic_irq(void)
{
int irq;
irq = i8259_irq();
if (irq >= 0)
do_IRQ(irq);
}
asmlinkage void plat_irq_dispatch(void)
{
unsigned pending = read_c0_status() & read_c0_cause();
if (pending & CAUSEF_IP2) /* COBALT_GALILEO_IRQ (18) */
galileo_irq();
else if (pending & CAUSEF_IP6) /* COBALT_VIA_IRQ (22) */
via_pic_irq();
else if (pending & CAUSEF_IP3) /* COBALT_ETH0_IRQ (19) */
do_IRQ(COBALT_CPU_IRQ + 3);
else if (pending & CAUSEF_IP4) /* COBALT_ETH1_IRQ (20) */
do_IRQ(COBALT_CPU_IRQ + 4);
else if (pending & CAUSEF_IP5) /* COBALT_SERIAL_IRQ (21) */
do_IRQ(COBALT_CPU_IRQ + 5);
else if (pending & CAUSEF_IP7) /* IRQ 23 */
do_IRQ(COBALT_CPU_IRQ + 7);
}
static struct irqaction irq_via = {
.handler = no_action,
.mask = CPU_MASK_NONE,
.name = "cascade"
};
void __init arch_init_irq(void)
{
/*
* Mask all Galileo interrupts. The Galileo
* handler is set in cobalt_timer_setup()
*/
GT_WRITE(GT_INTRMASK_OFS, 0);
init_i8259_irqs(); /* 0 ... 15 */
mips_cpu_irq_init(); /* 16 ... 23 */
/*
* Mask all cpu interrupts
* (except IE4, we already masked those at VIA level)
*/
change_c0_status(ST0_IM, IE_IRQ4);
setup_irq(COBALT_VIA_IRQ, &irq_via);
}
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