/*
* linux/arch/i386/kernel/irq.c
*
* Copyright (C) 1992 Linus Torvalds
*
* 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.
*/
/*
* 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/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/random.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/bitops.h>
#include <asm/smp.h>
#define CR0_NE 32
static unsigned char cache_21 = 0xff;
static unsigned char cache_A1 = 0xff;
#ifdef __SMP_PROF__
static unsigned int int_count[NR_CPUS][NR_IRQS] = {{0},};
#endif
void disable_irq(unsigned int irq_nr)
{
unsigned long flags;
unsigned char mask;
mask = 1 << (irq_nr & 7);
save_flags(flags);
if (irq_nr < 8) {
cli();
cache_21 |= mask;
outb(cache_21,0x21);
restore_flags(flags);
return;
}
cli();
cache_A1 |= mask;
outb(cache_A1,0xA1);
restore_flags(flags);
}
void enable_irq(unsigned int irq_nr)
{
unsigned long flags;
unsigned char mask;
mask = ~(1 << (irq_nr & 7));
save_flags(flags);
if (irq_nr < 8) {
cli();
cache_21 &= mask;
outb(cache_21,0x21);
restore_flags(flags);
return;
}
cli();
cache_A1 &= mask;
outb(cache_A1,0xA1);
restore_flags(flags);
}
/*
* 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 to keep the AT interrupt-controller
* happy. They are also written to be fast - and to disable interrupts
* as little as humanly possible.
*
* NOTE! These macros expand to three different handlers for each line: one
* complete handler that does all the fancy stuff (including signal handling),
* and one fast handler that is meant for simple IRQ's that want to be
* atomic. The specific handler is chosen depending on the SA_INTERRUPT
* flag when installing a handler. Finally, one "bad interrupt" handler, that
* is used when no handler is present.
*/
BUILD_IRQ(FIRST,0,0x01)
BUILD_IRQ(FIRST,1,0x02)
BUILD_IRQ(FIRST,2,0x04)
BUILD_IRQ(FIRST,3,0x08)
BUILD_IRQ(FIRST,4,0x10)
BUILD_IRQ(FIRST,5,0x20)
BUILD_IRQ(FIRST,6,0x40)
BUILD_IRQ(FIRST,7,0x80)
BUILD_IRQ(SECOND,8,0x01)
BUILD_IRQ(SECOND,9,0x02)
BUILD_IRQ(SECOND,10,0x04)
BUILD_IRQ(SECOND,11,0x08)
BUILD_IRQ(SECOND,12,0x10)
#ifdef __SMP__
BUILD_MSGIRQ(SECOND,13,0x20)
#else
BUILD_IRQ(SECOND,13,0x20)
#endif
BUILD_IRQ(SECOND,14,0x40)
BUILD_IRQ(SECOND,15,0x80)
#ifdef __SMP__
BUILD_RESCHEDIRQ(16)
#endif
/*
* Pointers to the low-level handlers: first the general ones, then the
* fast ones, then the bad ones.
*/
static void (*interrupt[17])(void) = {
IRQ0_interrupt, IRQ1_interrupt, IRQ2_interrupt, IRQ3_interrupt,
IRQ4_interrupt, IRQ5_interrupt, IRQ6_interrupt, IRQ7_interrupt,
IRQ8_interrupt, IRQ9_interrupt, IRQ10_interrupt, IRQ11_interrupt,
IRQ12_interrupt, IRQ13_interrupt, IRQ14_interrupt, IRQ15_interrupt
#ifdef __SMP__
,IRQ16_interrupt
#endif
};
static void (*fast_interrupt[16])(void) = {
fast_IRQ0_interrupt, fast_IRQ1_interrupt,
fast_IRQ2_interrupt, fast_IRQ3_interrupt,
fast_IRQ4_interrupt, fast_IRQ5_interrupt,
fast_IRQ6_interrupt, fast_IRQ7_interrupt,
fast_IRQ8_interrupt, fast_IRQ9_interrupt,
fast_IRQ10_interrupt, fast_IRQ11_interrupt,
fast_IRQ12_interrupt, fast_IRQ13_interrupt,
fast_IRQ14_interrupt, fast_IRQ15_interrupt
};
static void (*bad_interrupt[16])(void) = {
bad_IRQ0_interrupt, bad_IRQ1_interrupt,
bad_IRQ2_interrupt, 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,
bad_IRQ14_interrupt, bad_IRQ15_interrupt
};
/*
* Initial irq handlers.
*/
struct irqaction {
void (*handler)(int, struct pt_regs *);
unsigned long flags;
unsigned long mask;
const char *name;
};
static struct irqaction irq_action[16] = {
{ NULL, 0, 0, NULL }, { NULL, 0, 0, NULL },
{ NULL, 0, 0, NULL }, { NULL, 0, 0, NULL },
{ NULL, 0, 0, NULL }, { NULL, 0, 0, NULL },
{ NULL, 0, 0, NULL }, { NULL, 0, 0, NULL },
{ NULL, 0, 0, NULL }, { NULL, 0, 0, NULL },
{ NULL, 0, 0, NULL }, { NULL, 0, 0, NULL },
{ NULL, 0, 0, NULL }, { NULL, 0, 0, NULL },
{ NULL, 0, 0, NULL }, { NULL, 0, 0, NULL }
};
int get_irq_list(char *buf)
{
int i, len = 0;
struct irqaction * action = irq_action;
for (i = 0 ; i < 16 ; i++, action++) {
if (!action->handler)
continue;
len += sprintf(buf+len, "%3d: %8d %c %s\n",
i, kstat.interrupts[i],
(action->flags & SA_INTERRUPT) ? '+' : ' ',
action->name);
}
/*
* Linus - should you add NMI counts here ?????
*/
#ifdef __SMP_PROF__
len+=sprintf(buf+len, "IPI: %8lu received\n",
ipi_count);
#endif
return len;
}
#ifdef __SMP_PROF__
int get_smp_prof_list(char *buf) {
int i,j, len = 0;
struct irqaction * action = irq_action;
unsigned long sum_spins = 0;
unsigned long sum_spins_syscall = 0;
unsigned long sum_spins_sys_idle = 0;
unsigned long sum_smp_idle_count = 0;
for (i=0;i<=smp_num_cpus;i++) {
sum_spins+=smp_spins[i];
sum_spins_syscall+=smp_spins_syscall[i];
sum_spins_sys_idle+=smp_spins_sys_idle[i];
sum_smp_idle_count+=smp_idle_count[i];
}
len += sprintf(buf+len,"CPUS: %10i \n",
0==smp_num_cpus?1:smp_num_cpus);
len += sprintf(buf+len," SUM ");
for (i=0;i<smp_num_cpus;i++)
len += sprintf(buf+len," P%1d ",i);
len += sprintf(buf+len,"\n");
for (i = 0 ; i < NR_IRQS ; i++, action++) {
if (!action->handler)
continue;
len += sprintf(buf+len, "%3d: %10d ",
i, kstat.interrupts[i]);
for (j=0;j<smp_num_cpus;j++)
len+=sprintf(buf+len, "%10d ",int_count[j][i]);
len += sprintf(buf+len, "%c %s\n",
(action->flags & SA_INTERRUPT) ? '+' : ' ',
action->name);
}
len+=sprintf(buf+len, "LCK: %10lu",
sum_spins);
for (i=0;i<smp_num_cpus;i++)
len+=sprintf(buf+len," %10lu",smp_spins[i]);
len +=sprintf(buf+len," spins from int\n");
len+=sprintf(buf+len, "LCK: %10lu",
sum_spins_syscall);
for (i=0;i<smp_num_cpus;i++)
len+=sprintf(buf+len," %10lu",smp_spins_syscall[i]);
len +=sprintf(buf+len," spins from syscall\n");
len+=sprintf(buf+len, "LCK: %10lu",
sum_spins_sys_idle);
for (i=0;i<smp_num_cpus;i++)
len+=sprintf(buf+len," %10lu",smp_spins_sys_idle[i]);
len +=sprintf(buf+len," spins from sysidle\n");
len+=sprintf(buf+len,"IDLE %10lu",sum_smp_idle_count);
for (i=0;i<smp_num_cpus;i++)
len+=sprintf(buf+len," %10lu",smp_idle_count[i]);
len +=sprintf(buf+len," idle ticks\n");
len+=sprintf(buf+len, "IPI: %10lu received\n",
ipi_count);
return len;
}
#endif
/*
* do_IRQ handles IRQ's that have been installed without the
* SA_INTERRUPT flag: it uses the full signal-handling return
* and runs with other interrupts enabled. All relatively slow
* IRQ's should use this format: notably the keyboard/timer
* routines.
*/
asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
{
struct irqaction * action = irq + irq_action;
#ifdef __SMP__
if(smp_threads_ready && active_kernel_processor!=smp_processor_id())
panic("IRQ %d: active processor set wrongly(%d not %d).\n", irq, active_kernel_processor, smp_processor_id());
#endif
kstat.interrupts[irq]++;
#ifdef __SMP_PROF__
int_count[smp_processor_id()][irq]++;
#endif
if (action->flags & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
action->handler(irq, regs);
}
/*
* do_fast_IRQ handles IRQ's that don't need the fancy interrupt return
* stuff - the handler is also running with interrupts disabled unless
* it explicitly enables them later.
*/
asmlinkage void do_fast_IRQ(int irq)
{
struct irqaction * action = irq + irq_action;
#ifdef __SMP__
/* IRQ 13 is allowed - thats an invalidate */
if(smp_threads_ready && active_kernel_processor!=smp_processor_id() && irq!=13)
panic("fast_IRQ %d: active processor set wrongly(%d not %d).\n", irq, active_kernel_processor, smp_processor_id());
#endif
kstat.interrupts[irq]++;
#ifdef __SMP_PROF__
int_count[smp_processor_id()][irq]++;
#endif
if (action->flags & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
action->handler(irq, NULL);
}
#define SA_PROBE SA_ONESHOT
int request_irq(unsigned int irq, void (*handler)(int, struct pt_regs *),
unsigned long irqflags, const char * devname)
{
struct irqaction * action;
unsigned long flags;
if (irq > 15)
return -EINVAL;
action = irq + irq_action;
if (action->handler)
return -EBUSY;
if (!handler)
return -EINVAL;
if (irqflags & SA_SAMPLE_RANDOM)
rand_initialize_irq(irq);
save_flags(flags);
cli();
action->handler = handler;
action->flags = irqflags;
action->mask = 0;
action->name = devname;
if (!(action->flags & SA_PROBE)) { /* SA_ONESHOT is used by probing */
if (action->flags & SA_INTERRUPT)
set_intr_gate(0x20+irq,fast_interrupt[irq]);
else
set_intr_gate(0x20+irq,interrupt[irq]);
}
if (irq < 8) {
cache_21 &= ~(1<<irq);
outb(cache_21,0x21);
} else {
cache_21 &= ~(1<<2);
cache_A1 &= ~(1<<(irq-8));
outb(cache_21,0x21);
outb(cache_A1,0xA1);
}
restore_flags(flags);
return 0;
}
void free_irq(unsigned int irq)
{
struct irqaction * action = irq + irq_action;
unsigned long flags;
if (irq > 15) {
printk("Trying to free IRQ%d\n",irq);
return;
}
if (!action->handler) {
printk("Trying to free free IRQ%d\n",irq);
return;
}
save_flags(flags);
cli();
if (irq < 8) {
cache_21 |= 1 << irq;
outb(cache_21,0x21);
} else {
cache_A1 |= 1 << (irq-8);
outb(cache_A1,0xA1);
}
set_intr_gate(0x20+irq,bad_interrupt[irq]);
action->handler = NULL;
action->flags = 0;
action->mask = 0;
action->name = NULL;
restore_flags(flags);
}
#ifndef __SMP__
/*
* Note that on a 486, we don't want to do a SIGFPE on a irq13
* as the irq is unreliable, and exception 16 works correctly
* (ie as explained in the intel literature). On a 386, you
* can't use exception 16 due to bad IBM design, so we have to
* rely on the less exact irq13.
*
* Careful.. Not only is IRQ13 unreliable, but it is also
* leads to races. IBM designers who came up with it should
* be shot.
*/
static void math_error_irq(int cpl, struct pt_regs *regs)
{
outb(0,0xF0);
if (ignore_irq13 || !hard_math)
return;
math_error();
}
#endif
static void no_action(int cpl, struct pt_regs * regs) { }
unsigned long probe_irq_on (void)
{
unsigned int i, irqs = 0, irqmask;
unsigned long delay;
/* first, snaffle up any unassigned irqs */
for (i = 15; i > 0; i--) {
if (!request_irq(i, no_action, SA_PROBE, "probe")) {
enable_irq(i);
irqs |= (1 << i);
}
}
/* wait for spurious interrupts to mask themselves out again */
for (delay = jiffies + 2; delay > jiffies; ); /* min 10ms delay */
/* now filter out any obviously spurious interrupts */
irqmask = (((unsigned int)cache_A1)<<8) | (unsigned int)cache_21;
for (i = 15; i > 0; i--) {
if (irqs & (1 << i) & irqmask) {
irqs ^= (1 << i);
free_irq(i);
}
}
#ifdef DEBUG
printk("probe_irq_on: irqs=0x%04x irqmask=0x%04x\n", irqs, irqmask);
#endif
return irqs;
}
int probe_irq_off (unsigned long irqs)
{
unsigned int i, irqmask;
irqmask = (((unsigned int)cache_A1)<<8) | (unsigned int)cache_21;
for (i = 15; i > 0; i--) {
if (irqs & (1 << i)) {
free_irq(i);
}
}
#ifdef DEBUG
printk("probe_irq_off: irqs=0x%04x irqmask=0x%04x\n", irqs, irqmask);
#endif
irqs &= irqmask;
if (!irqs)
return 0;
i = ffz(~irqs);
if (irqs != (irqs & (1 << i)))
i = -i;
return i;
}
void init_IRQ(void)
{
int i;
static unsigned char smptrap=0;
if(smptrap)
return;
smptrap=1;
/* set the clock to 100 Hz */
outb_p(0x34,0x43); /* binary, mode 2, LSB/MSB, ch 0 */
outb_p(LATCH & 0xff , 0x40); /* LSB */
outb(LATCH >> 8 , 0x40); /* MSB */
for (i = 0; i < 16 ; i++)
set_intr_gate(0x20+i,bad_interrupt[i]);
/* This bit is a hack because we don't send timer messages to all processors yet */
/* It has to here .. it doesnt work if you put it down the bottom - assembler explodes 8) */
#ifdef __SMP__
set_intr_gate(0x20+i, interrupt[i]); /* IRQ '16' - IPI for rescheduling */
#endif
if (request_irq(2, no_action, SA_INTERRUPT, "cascade"))
printk("Unable to get IRQ2 for cascade.\n");
#ifndef __SMP__
if (request_irq(13,math_error_irq, 0, "math error"))
printk("Unable to get IRQ13 for math-error handler.\n");
#else
if (request_irq(13, smp_message_irq, SA_INTERRUPT, "IPI"))
printk("Unable to get IRQ13 for IPI.\n");
#endif
request_region(0x20,0x20,"pic1");
request_region(0xa0,0x20,"pic2");
}