/*
* linux/arch/cris/kernel/irq.c
*
* Copyright (c) 2000-2002 Axis Communications AB
*
* Authors: Bjorn Wesen (bjornw@axis.com)
*
* This file contains the interrupt vectors and some
* helper functions
*
*/
#include <asm/irq.h>
#include <asm/current.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/init.h>
#define crisv10_mask_irq(irq_nr) (*R_VECT_MASK_CLR = 1 << (irq_nr));
#define crisv10_unmask_irq(irq_nr) (*R_VECT_MASK_SET = 1 << (irq_nr));
extern void kgdb_init(void);
extern void breakpoint(void);
/* don't use set_int_vector, it bypasses the linux interrupt handlers. it is
* global just so that the kernel gdb can use it.
*/
void
set_int_vector(int n, irqvectptr addr)
{
etrax_irv->v[n + 0x20] = (irqvectptr)addr;
}
/* the breakpoint vector is obviously not made just like the normal irq handlers
* but needs to contain _code_ to jump to addr.
*
* the BREAK n instruction jumps to IBR + n * 8
*/
void
set_break_vector(int n, irqvectptr addr)
{
unsigned short *jinstr = (unsigned short *)&etrax_irv->v[n*2];
unsigned long *jaddr = (unsigned long *)(jinstr + 1);
/* if you don't know what this does, do not touch it! */
*jinstr = 0x0d3f;
*jaddr = (unsigned long)addr;
/* 00000026 <clrlop+1a> 3f0d82000000 jump 0x82 */
}
/*
* This builds up the IRQ handler stubs using some ugly macros in irq.h
*
* These macros create the low-level assembly IRQ routines that do all
* the operations that are needed. They are also written to be fast - and to
* disable interrupts as little as humanly possible.
*
*/
/* IRQ0 and 1 are special traps */
void hwbreakpoint(void);
void IRQ1_interrupt(void);
BUILD_TIMER_IRQ(2, 0x04) /* the timer interrupt is somewhat special */
BUILD_IRQ(3, 0x08)
BUILD_IRQ(4, 0x10)
BUILD_IRQ(5, 0x20)
BUILD_IRQ(6, 0x40)
BUILD_IRQ(7, 0x80)
BUILD_IRQ(8, 0x100)
BUILD_IRQ(9, 0x200)
BUILD_IRQ(10, 0x400)
BUILD_IRQ(11, 0x800)
BUILD_IRQ(12, 0x1000)
BUILD_IRQ(13, 0x2000)
void mmu_bus_fault(void); /* IRQ 14 is the bus fault interrupt */
void multiple_interrupt(void); /* IRQ 15 is the multiple IRQ interrupt */
BUILD_IRQ(16, 0x10000 | 0x20000) /* ethernet tx interrupt needs to block rx */
BUILD_IRQ(17, 0x20000 | 0x10000) /* ...and vice versa */
BUILD_IRQ(18, 0x40000)
BUILD_IRQ(19, 0x80000)
BUILD_IRQ(20, 0x100000)
BUILD_IRQ(21, 0x200000)
BUILD_IRQ(22, 0x400000)
BUILD_IRQ(23, 0x800000)
BUILD_IRQ(24, 0x1000000)
BUILD_IRQ(25, 0x2000000)
/* IRQ 26-30 are reserved */
BUILD_IRQ(31, 0x80000000)
/*
* Pointers to the low-level handlers
*/
static void (*interrupt[NR_IRQS])(void) = {
NULL, NULL, IRQ2_interrupt, IRQ3_interrupt,
IRQ4_interrupt, IRQ5_interrupt, IRQ6_interrupt, IRQ7_interrupt,
IRQ8_interrupt, IRQ9_interrupt, IRQ10_interrupt, IRQ11_interrupt,
IRQ12_interrupt, IRQ13_interrupt, NULL, NULL,
IRQ16_interrupt, IRQ17_interrupt, IRQ18_interrupt, IRQ19_interrupt,
IRQ20_interrupt, IRQ21_interrupt, IRQ22_interrupt, IRQ23_interrupt,
IRQ24_interrupt, IRQ25_interrupt, NULL, NULL, NULL, NULL, NULL,
IRQ31_interrupt
};
static void enable_crisv10_irq(struct irq_data *data)
{
crisv10_unmask_irq(data->irq);
}
static void disable_crisv10_irq(struct irq_data *data)
{
crisv10_mask_irq(data->irq);
}
static struct irq_chip crisv10_irq_type = {
.name = "CRISv10",
.irq_shutdown = disable_crisv10_irq,
.irq_enable = enable_crisv10_irq,
.irq_disable = disable_crisv10_irq,
};
void weird_irq(void);
void system_call(void); /* from entry.S */
void do_sigtrap(void); /* from entry.S */
void gdb_handle_breakpoint(void); /* from entry.S */
extern void do_IRQ(int irq, struct pt_regs * regs);
/* Handle multiple IRQs */
void do_multiple_IRQ(struct pt_regs* regs)
{
int bit;
unsigned masked;
unsigned mask;
unsigned ethmask = 0;
/* Get interrupts to mask and handle */
mask = masked = *R_VECT_MASK_RD;
/* Never mask timer IRQ */
mask &= ~(IO_MASK(R_VECT_MASK_RD, timer0));
/*
* If either ethernet interrupt (rx or tx) is active then block
* the other one too. Unblock afterwards also.
*/
if (mask &
(IO_STATE(R_VECT_MASK_RD, dma0, active) |
IO_STATE(R_VECT_MASK_RD, dma1, active))) {
ethmask = (IO_MASK(R_VECT_MASK_RD, dma0) |
IO_MASK(R_VECT_MASK_RD, dma1));
}
/* Block them */
*R_VECT_MASK_CLR = (mask | ethmask);
/* An extra irq_enter here to prevent softIRQs to run after
* each do_IRQ. This will decrease the interrupt latency.
*/
irq_enter();
/* Handle all IRQs */
for (bit = 2; bit < 32; bit++) {
if (masked & (1 << bit)) {
do_IRQ(bit, regs);
}
}
/* This irq_exit() will trigger the soft IRQs. */
irq_exit();
/* Unblock the IRQs again */
*R_VECT_MASK_SET = (masked | ethmask);
}
/* init_IRQ() is called by start_kernel and is responsible for fixing IRQ masks and
setting the irq vector table.
*/
void __init init_IRQ(void)
{
int i;
/* clear all interrupt masks */
*R_IRQ_MASK0_CLR = 0xffffffff;
*R_IRQ_MASK1_CLR = 0xffffffff;
*R_IRQ_MASK2_CLR = 0xffffffff;
*R_VECT_MASK_CLR = 0xffffffff;
for (i = 0; i < 256; i++)
etrax_irv->v[i] = weird_irq;
/* Initialize IRQ handler descriptors. */
for(i = 2; i < NR_IRQS; i++) {
irq_set_chip_and_handler(i, &crisv10_irq_type,
handle_simple_irq);
set_int_vector(i, interrupt[i]);
}
/* the entries in the break vector contain actual code to be
executed by the associated break handler, rather than just a jump
address. therefore we need to setup a default breakpoint handler
for all breakpoints */
for (i = 0; i < 16; i++)
set_break_vector(i, do_sigtrap);
/* except IRQ 15 which is the multiple-IRQ handler on Etrax100 */
set_int_vector(15, multiple_interrupt);
/* 0 and 1 which are special breakpoint/NMI traps */
set_int_vector(0, hwbreakpoint);
set_int_vector(1, IRQ1_interrupt);
/* and irq 14 which is the mmu bus fault handler */
set_int_vector(14, mmu_bus_fault);
/* setup the system-call trap, which is reached by BREAK 13 */
set_break_vector(13, system_call);
/* setup a breakpoint handler for debugging used for both user and
kernel mode debugging (which is why it is not inside an ifdef
CONFIG_ETRAX_KGDB) */
set_break_vector(8, gdb_handle_breakpoint);
#ifdef CONFIG_ETRAX_KGDB
/* setup kgdb if its enabled, and break into the debugger */
kgdb_init();
breakpoint();
#endif
}