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/* $Id: irq.c,v 1.18 2001/11/21 13:40:18 bjornw Exp $
*
* linux/arch/cris/kernel/irq.c
*
* Copyright (c) 2000,2001 Axis Communications AB
*
* Authors: Bjorn Wesen (bjornw@axis.com)
*
* This file contains the code used by various IRQ handling routines:
* asking for different IRQ's should be done through these routines
* instead of just grabbing them. Thus setups with different IRQ numbers
* shouldn't result in any weird surprises, and installing new handlers
* should be easier.
*
* Notice Linux/CRIS: these routines do not care about SMP
*
*/
/*
* IRQ's are in fact implemented a bit like signal handlers for the kernel.
* Naturally it's not a 1:1 relation, but there are similarities.
*/
#include <linux/config.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/init.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/bitops.h>
#include <asm/svinto.h>
char *hw_bp_msg = "BP 0x%x\n";
static inline void
mask_irq(unsigned int irq_nr)
{
*R_VECT_MASK_CLR = 1 << irq_nr;
}
static inline void
unmask_irq(unsigned int irq_nr)
{
*R_VECT_MASK_SET = 1 << irq_nr;
}
void
disable_irq(unsigned int irq_nr)
{
unsigned long flags;
save_flags(flags);
cli();
mask_irq(irq_nr);
restore_flags(flags);
}
void
enable_irq(unsigned int irq_nr)
{
unsigned long flags;
save_flags(flags);
cli();
unmask_irq(irq_nr);
restore_flags(flags);
}
unsigned long
probe_irq_on()
{
return 0;
}
int
probe_irq_off(unsigned long x)
{
return 0;
}
irqvectptr irq_shortcuts[NR_IRQS]; /* vector of shortcut jumps after the irq prologue */
/* 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, irqvectptr saddr)
{
/* remember the shortcut entry point, after the prologue */
irq_shortcuts[n] = saddr;
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)
BUILD_IRQ(17, 0x20000)
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 (*sinterrupt[NR_IRQS])(void) = {
NULL, NULL, sIRQ2_interrupt, sIRQ3_interrupt,
sIRQ4_interrupt, sIRQ5_interrupt, sIRQ6_interrupt, sIRQ7_interrupt,
sIRQ8_interrupt, sIRQ9_interrupt, sIRQ10_interrupt, sIRQ11_interrupt,
sIRQ12_interrupt, sIRQ13_interrupt, NULL, NULL,
sIRQ16_interrupt, sIRQ17_interrupt, sIRQ18_interrupt, sIRQ19_interrupt,
sIRQ20_interrupt, sIRQ21_interrupt, sIRQ22_interrupt, sIRQ23_interrupt,
sIRQ24_interrupt, sIRQ25_interrupt, NULL, NULL, NULL, NULL, NULL,
sIRQ31_interrupt
};
static void (*bad_interrupt[NR_IRQS])(void) = {
NULL, NULL,
NULL, bad_IRQ3_interrupt,
bad_IRQ4_interrupt, bad_IRQ5_interrupt,
bad_IRQ6_interrupt, bad_IRQ7_interrupt,
bad_IRQ8_interrupt, bad_IRQ9_interrupt,
bad_IRQ10_interrupt, bad_IRQ11_interrupt,
bad_IRQ12_interrupt, bad_IRQ13_interrupt,
NULL, NULL,
bad_IRQ16_interrupt, bad_IRQ17_interrupt,
bad_IRQ18_interrupt, bad_IRQ19_interrupt,
bad_IRQ20_interrupt, bad_IRQ21_interrupt,
bad_IRQ22_interrupt, bad_IRQ23_interrupt,
bad_IRQ24_interrupt, bad_IRQ25_interrupt,
NULL, NULL, NULL, NULL, NULL,
bad_IRQ31_interrupt
};
/*
* Initial irq handlers.
*/
static struct irqaction *irq_action[NR_IRQS] = {
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL
};
int get_irq_list(char *buf)
{
int i, len = 0;
struct irqaction * action;
for (i = 0; i < NR_IRQS; i++) {
action = irq_action[i];
if (!action)
continue;
len += sprintf(buf+len, "%2d: %10u %c %s",
i, kstat.irqs[0][i],
(action->flags & SA_INTERRUPT) ? '+' : ' ',
action->name);
for (action = action->next; action; action = action->next) {
len += sprintf(buf+len, ",%s %s",
(action->flags & SA_INTERRUPT) ? " +" : "",
action->name);
}
len += sprintf(buf+len, "\n");
}
return len;
}
/* called by the assembler IRQ entry functions defined in irq.h
* to dispatch the interrupts to registred handlers
* interrupts are disabled upon entry - depending on if the
* interrupt was registred with SA_INTERRUPT or not, interrupts
* are re-enabled or not.
*/
asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
{
struct irqaction *action;
int do_random, cpu;
cpu = smp_processor_id();
irq_enter(cpu);
kstat.irqs[cpu][irq]++;
action = irq_action[irq];
if (action) {
if (!(action->flags & SA_INTERRUPT))
__sti();
action = irq_action[irq];
do_random = 0;
do {
do_random |= action->flags;
action->handler(irq, action->dev_id, regs);
action = action->next;
} while (action);
if (do_random & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
__cli();
}
irq_exit(cpu);
if (softirq_pending(cpu))
do_softirq();
/* unmasking and bottom half handling is done magically for us. */
}
/* this function links in a handler into the chain of handlers for the
given irq, and if the irq has never been registred, the appropriate
handler is entered into the interrupt vector
*/
int setup_etrax_irq(int irq, struct irqaction * new)
{
int shared = 0;
struct irqaction *old, **p;
unsigned long flags;
p = irq_action + irq;
if ((old = *p) != NULL) {
/* Can't share interrupts unless both agree to */
if (!(old->flags & new->flags & SA_SHIRQ))
return -EBUSY;
/* Can't share interrupts unless both are same type */
if ((old->flags ^ new->flags) & SA_INTERRUPT)
return -EBUSY;
/* add new interrupt at end of irq queue */
do {
p = &old->next;
old = *p;
} while (old);
shared = 1;
}
if (new->flags & SA_SAMPLE_RANDOM)
rand_initialize_irq(irq);
save_flags(flags);
cli();
*p = new;
if (!shared) {
/* if the irq wasn't registred before, enter it into the vector table
and unmask it physically
*/
set_int_vector(irq, interrupt[irq], sinterrupt[irq]);
unmask_irq(irq);
}
restore_flags(flags);
return 0;
}
/* this function is called by a driver to register an irq handler
Valid flags:
SA_INTERRUPT -> it's a fast interrupt, handler called with irq disabled and
no signal checking etc is performed upon exit
SA_SHIRQ -> the interrupt can be shared between different handlers, the handler
is required to check if the irq was "aimed" at it explicitely
SA_RANDOM -> the interrupt will add to the random generators entropy
*/
int request_irq(unsigned int irq,
void (*handler)(int, void *, struct pt_regs *),
unsigned long irqflags,
const char * devname,
void *dev_id)
{
int retval;
struct irqaction * action;
/* interrupts 0 and 1 are hardware breakpoint and NMI and we can't support
these yet. interrupt 15 is the multiple irq, it's special. */
if(irq < 2 || irq == 15 || irq >= NR_IRQS)
return -EINVAL;
if(!handler)
return -EINVAL;
/* allocate and fill in a handler structure and setup the irq */
action = (struct irqaction *)kmalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action)
return -ENOMEM;
action->handler = handler;
action->flags = irqflags;
action->mask = 0;
action->name = devname;
action->next = NULL;
action->dev_id = dev_id;
retval = setup_etrax_irq(irq, action);
if (retval)
kfree(action);
return retval;
}
void free_irq(unsigned int irq, void *dev_id)
{
struct irqaction * action, **p;
unsigned long flags;
if (irq >= NR_IRQS) {
printk("Trying to free IRQ%d\n",irq);
return;
}
for (p = irq + irq_action; (action = *p) != NULL; p = &action->next) {
if (action->dev_id != dev_id)
continue;
/* Found it - now free it */
save_flags(flags);
cli();
*p = action->next;
if (!irq_action[irq]) {
mask_irq(irq);
set_int_vector(irq, bad_interrupt[irq], 0);
}
restore_flags(flags);
kfree(action);
return;
}
printk("Trying to free free IRQ%d\n",irq);
}
void weird_irq(void)
{
__asm__("di");
printk("weird irq\n");
while(1);
}
/* init_IRQ() is called by start_kernel and is responsible for fixing IRQ masks and
setting the irq vector table to point to bad_interrupt ptrs.
*/
void system_call(void); /* from entry.S */
void do_sigtrap(void); /* from entry.S */
void gdb_handle_breakpoint(void); /* from entry.S */
void __init
init_IRQ(void)
{
int i;
/* clear all interrupt masks */
#ifndef CONFIG_SVINTO_SIM
*R_IRQ_MASK0_CLR = 0xffffffff;
*R_IRQ_MASK1_CLR = 0xffffffff;
*R_IRQ_MASK2_CLR = 0xffffffff;
#endif
*R_VECT_MASK_CLR = 0xffffffff;
/* clear the shortcut entry points */
for(i = 0; i < NR_IRQS; i++)
irq_shortcuts[i] = NULL;
for (i = 0; i < 256; i++)
etrax_irv->v[i] = weird_irq;
/* 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);
/* set all etrax irq's to the bad handlers */
for (i = 2; i < NR_IRQS; i++)
set_int_vector(i, bad_interrupt[i], 0);
/* except IRQ 15 which is the multiple-IRQ handler on Etrax100 */
set_int_vector(15, multiple_interrupt, 0);
/* 0 and 1 which are special breakpoint/NMI traps */
set_int_vector(0, hwbreakpoint, 0);
set_int_vector(1, IRQ1_interrupt, 0);
/* and irq 14 which is the mmu bus fault handler */
set_int_vector(14, mmu_bus_fault, 0);
/* 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
}
#if defined(CONFIG_PROC_FS) && defined(CONFIG_SYSCTL)
/* Used by other archs to show/control IRQ steering during SMP */
void __init
init_irq_proc(void)
{
}
#endif
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