/*
* 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/malloc.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
static inline void mask_irq(unsigned int irq_nr)
{
unsigned char mask;
mask = 1 << (irq_nr & 7);
if (irq_nr < 8) {
cache_21 |= mask;
outb(cache_21,0x21);
} else {
cache_A1 |= mask;
outb(cache_A1,0xA1);
}
}
static inline void unmask_irq(unsigned int irq_nr)
{
unsigned char mask;
mask = ~(1 << (irq_nr & 7));
if (irq_nr < 8) {
cache_21 &= mask;
outb(cache_21,0x21);
} else {
cache_A1 &= mask;
outb(cache_A1,0xA1);
}
}
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);
}
/*
* 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.
*
* The timer interrupt is handled specially to insure that the jiffies
* variable is updated at all times. Specifically, the timer interrupt is
* just like the complete handlers except that it is invoked with interrupts
* disabled and should never re-enable them. If other interrupts were
* allowed to be processed while the timer interrupt is active, then the
* other interrupts would have to avoid using the jiffies variable for delay
* and interval timing operations to avoid hanging the system.
*/
BUILD_TIMER_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.
*/
static void no_action(int cpl, void *dev_id, struct pt_regs *regs) { }
#ifdef __SMP__
/*
* On SMP boards, irq13 is used for interprocessor interrupts (IPI's).
*/
static struct irqaction irq13 = { smp_message_irq, SA_INTERRUPT, 0, "IPI", NULL, NULL };
#else
/*
* 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, void *dev_id, struct pt_regs *regs)
{
outb(0,0xF0);
if (ignore_irq13 || !hard_math)
return;
math_error();
}
static struct irqaction irq13 = { math_error_irq, 0, 0, "math error", NULL, NULL };
#endif
/*
* IRQ2 is cascade interrupt to second interrupt controller
*/
static struct irqaction irq2 = { no_action, 0, 0, "cascade", NULL, NULL};
static struct irqaction *irq_action[16] = {
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 < 16 ; i++) {
action = irq_action[i];
if (!action)
continue;
len += sprintf(buf+len, "%2d: %10u %c %s",
i, kstat.interrupts[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");
}
/*
* 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;
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++) {
int cpunum = cpu_logical_map[i];
sum_spins+=smp_spins[cpunum];
sum_spins_syscall+=smp_spins_syscall[cpunum];
sum_spins_sys_idle+=smp_spins_sys_idle[cpunum];
sum_smp_idle_count+=smp_idle_count[cpunum];
}
len += sprintf(buf+len,"CPUS: %10i \n", smp_num_cpus);
len += sprintf(buf+len," SUM ");
for (i=0;i<smp_num_cpus;i++)
len += sprintf(buf+len," P%1d ",cpu_logical_map[i]);
len += sprintf(buf+len,"\n");
for (i = 0 ; i < NR_IRQS ; i++) {
action = *(i + irq_action);
if (!action || !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[cpu_logical_map[j]][i]);
len += sprintf(buf+len, "%c %s",
(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");
}
len+=sprintf(buf+len, "LCK: %10lu",
sum_spins);
for (i=0;i<smp_num_cpus;i++)
len+=sprintf(buf+len," %10lu",smp_spins[cpu_logical_map[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[cpu_logical_map[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[cpu_logical_map[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[cpu_logical_map[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);
int do_random = 0;
#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
while (action) {
do_random |= action->flags;
action->handler(irq, action->dev_id, regs);
action = action->next;
}
if (do_random & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
}
/*
* 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);
int do_random = 0;
#ifdef __SMP__
/* IRQ 13 is allowed - that's a flush tlb */
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
while (action) {
do_random |= action->flags;
action->handler(irq, action->dev_id, NULL);
action = action->next;
}
if (do_random & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
}
int setup_x86_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 (new->flags & SA_INTERRUPT)
set_intr_gate(0x20+irq,fast_interrupt[irq]);
else
set_intr_gate(0x20+irq,interrupt[irq]);
unmask_irq(irq);
}
restore_flags(flags);
return 0;
}
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;
if (irq > 15)
return -EINVAL;
if (!handler)
return -EINVAL;
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_x86_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 > 15) {
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[irq_action]) {
mask_irq(irq);
set_intr_gate(0x20+irq,bad_interrupt[irq]);
}
restore_flags(flags);
kfree(action);
return;
}
printk("Trying to free free IRQ%d\n",irq);
}
unsigned long probe_irq_on (void)
{
unsigned int i, irqs = 0, irqmask;
unsigned long delay;
/* first, enable any unassigned irqs */
for (i = 15; i > 0; i--) {
if (!irq_action[i]) {
enable_irq(i);
irqs |= (1 << i);
}
}
/* wait for spurious interrupts to mask themselves out again */
for (delay = jiffies + HZ/10; delay > jiffies; )
/* about 100ms delay */;
/* now filter out any obviously spurious interrupts */
irqmask = (((unsigned int)cache_A1)<<8) | (unsigned int)cache_21;
return irqs & ~irqmask;
}
int probe_irq_off (unsigned long irqs)
{
unsigned int i, irqmask;
irqmask = (((unsigned int)cache_A1)<<8) | (unsigned int)cache_21;
#ifdef DEBUG
printk("probe_irq_off: irqs=0x%04lx 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 be here .. it doesn't 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
request_region(0x20,0x20,"pic1");
request_region(0xa0,0x20,"pic2");
setup_x86_irq(2, &irq2);
setup_x86_irq(13, &irq13);
}
