blob: 871f8ecb156be71eea74d60256ee8fa8bf235829 [file] [log] [blame]
#include <linux/linkage.h>
#include <linux/config.h>
#include <linux/ptrace.h>
#include <linux/errno.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/smp_lock.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <asm/acpi.h>
#include <asm/atomic.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/hw_irq.h>
#include <asm/bitops.h>
#include <asm/pgtable.h>
#include <asm/delay.h>
#include <asm/desc.h>
#include <asm/apic.h>
#include <linux/irq.h>
/* When we have things working, we can switch to always use
IOAPIC. --pavel */
/*
* Common place to define all x86 IRQ vectors
*
* This builds up the IRQ handler stubs using some ugly macros in irq.h
*
* These macros create the low-level assembly IRQ routines that save
* register context and call do_IRQ(). do_IRQ() then does all the
* operations that are needed to keep the AT (or SMP IOAPIC)
* interrupt-controller happy.
*/
#define BI(x,y) \
BUILD_IRQ(x##y)
#define BUILD_16_IRQS(x) \
BI(x,0) BI(x,1) BI(x,2) BI(x,3) \
BI(x,4) BI(x,5) BI(x,6) BI(x,7) \
BI(x,8) BI(x,9) BI(x,a) BI(x,b) \
BI(x,c) BI(x,d) BI(x,e) BI(x,f)
/*
* ISA PIC or low IO-APIC triggered (INTA-cycle or APIC) interrupts:
* (these are usually mapped to vectors 0x20-0x2f)
*/
BUILD_16_IRQS(0x0)
#ifdef CONFIG_X86_IO_APIC
/*
* The IO-APIC gives us many more interrupt sources. Most of these
* are unused but an SMP system is supposed to have enough memory ...
* sometimes (mostly wrt. hw bugs) we get corrupted vectors all
* across the spectrum, so we really want to be prepared to get all
* of these. Plus, more powerful systems might have more than 64
* IO-APIC registers.
*
* (these are usually mapped into the 0x30-0xff vector range)
*/
BUILD_16_IRQS(0x1) BUILD_16_IRQS(0x2) BUILD_16_IRQS(0x3)
BUILD_16_IRQS(0x4) BUILD_16_IRQS(0x5) BUILD_16_IRQS(0x6) BUILD_16_IRQS(0x7)
BUILD_16_IRQS(0x8) BUILD_16_IRQS(0x9) BUILD_16_IRQS(0xa) BUILD_16_IRQS(0xb)
BUILD_16_IRQS(0xc) BUILD_16_IRQS(0xd)
#endif
#undef BUILD_16_IRQS
#undef BI
#define IRQ(x,y) \
IRQ##x##y##_interrupt
#define IRQLIST_16(x) \
IRQ(x,0), IRQ(x,1), IRQ(x,2), IRQ(x,3), \
IRQ(x,4), IRQ(x,5), IRQ(x,6), IRQ(x,7), \
IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \
IRQ(x,c), IRQ(x,d), IRQ(x,e), IRQ(x,f)
void (*interrupt[NR_IRQS])(void) = {
IRQLIST_16(0x0),
#ifdef CONFIG_X86_IO_APIC
IRQLIST_16(0x1), IRQLIST_16(0x2), IRQLIST_16(0x3),
IRQLIST_16(0x4), IRQLIST_16(0x5), IRQLIST_16(0x6), IRQLIST_16(0x7),
IRQLIST_16(0x8), IRQLIST_16(0x9), IRQLIST_16(0xa), IRQLIST_16(0xb),
IRQLIST_16(0xc), IRQLIST_16(0xd)
#endif
};
#undef IRQ
#undef IRQLIST_16
/*
* This is the 'legacy' 8259A Programmable Interrupt Controller,
* present in the majority of PC/AT boxes.
* plus some generic x86 specific things if generic specifics makes
* any sense at all.
* this file should become arch/i386/kernel/irq.c when the old irq.c
* moves to arch independent land
*/
spinlock_t i8259A_lock = SPIN_LOCK_UNLOCKED;
static void end_8259A_irq (unsigned int irq)
{
if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
enable_8259A_irq(irq);
}
#define shutdown_8259A_irq disable_8259A_irq
void mask_and_ack_8259A(unsigned int);
static unsigned int startup_8259A_irq(unsigned int irq)
{
enable_8259A_irq(irq);
return 0; /* never anything pending */
}
static struct hw_interrupt_type i8259A_irq_type = {
"XT-PIC",
startup_8259A_irq,
shutdown_8259A_irq,
enable_8259A_irq,
disable_8259A_irq,
mask_and_ack_8259A,
end_8259A_irq,
NULL
};
/*
* 8259A PIC functions to handle ISA devices:
*/
/*
* This contains the irq mask for both 8259A irq controllers,
*/
static unsigned int cached_irq_mask = 0xffff;
#define __byte(x,y) (((unsigned char *)&(y))[x])
#define cached_21 (__byte(0,cached_irq_mask))
#define cached_A1 (__byte(1,cached_irq_mask))
/*
* Not all IRQs can be routed through the IO-APIC, eg. on certain (older)
* boards the timer interrupt is not really connected to any IO-APIC pin,
* it's fed to the master 8259A's IR0 line only.
*
* Any '1' bit in this mask means the IRQ is routed through the IO-APIC.
* this 'mixed mode' IRQ handling costs nothing because it's only used
* at IRQ setup time.
*/
unsigned long io_apic_irqs;
void disable_8259A_irq(unsigned int irq)
{
unsigned int mask = 1 << irq;
unsigned long flags;
spin_lock_irqsave(&i8259A_lock, flags);
cached_irq_mask |= mask;
if (irq & 8)
outb(cached_A1,0xA1);
else
outb(cached_21,0x21);
spin_unlock_irqrestore(&i8259A_lock, flags);
}
void enable_8259A_irq(unsigned int irq)
{
unsigned int mask = ~(1 << irq);
unsigned long flags;
spin_lock_irqsave(&i8259A_lock, flags);
cached_irq_mask &= mask;
if (irq & 8)
outb(cached_A1,0xA1);
else
outb(cached_21,0x21);
spin_unlock_irqrestore(&i8259A_lock, flags);
}
int i8259A_irq_pending(unsigned int irq)
{
unsigned int mask = 1<<irq;
unsigned long flags;
int ret;
spin_lock_irqsave(&i8259A_lock, flags);
if (irq < 8)
ret = inb(0x20) & mask;
else
ret = inb(0xA0) & (mask >> 8);
spin_unlock_irqrestore(&i8259A_lock, flags);
return ret;
}
void make_8259A_irq(unsigned int irq)
{
disable_irq_nosync(irq);
io_apic_irqs &= ~(1<<irq);
irq_desc[irq].handler = &i8259A_irq_type;
enable_irq(irq);
}
/*
* This function assumes to be called rarely. Switching between
* 8259A registers is slow.
* This has to be protected by the irq controller spinlock
* before being called.
*/
static inline int i8259A_irq_real(unsigned int irq)
{
int value;
int irqmask = 1<<irq;
if (irq < 8) {
outb(0x0B,0x20); /* ISR register */
value = inb(0x20) & irqmask;
outb(0x0A,0x20); /* back to the IRR register */
return value;
}
outb(0x0B,0xA0); /* ISR register */
value = inb(0xA0) & (irqmask >> 8);
outb(0x0A,0xA0); /* back to the IRR register */
return value;
}
/*
* Careful! The 8259A is a fragile beast, it pretty
* much _has_ to be done exactly like this (mask it
* first, _then_ send the EOI, and the order of EOI
* to the two 8259s is important!
*/
void mask_and_ack_8259A(unsigned int irq)
{
unsigned int irqmask = 1 << irq;
unsigned long flags;
spin_lock_irqsave(&i8259A_lock, flags);
/*
* Lightweight spurious IRQ detection. We do not want
* to overdo spurious IRQ handling - it's usually a sign
* of hardware problems, so we only do the checks we can
* do without slowing down good hardware unnecesserily.
*
* Note that IRQ7 and IRQ15 (the two spurious IRQs
* usually resulting from the 8259A-1|2 PICs) occur
* even if the IRQ is masked in the 8259A. Thus we
* can check spurious 8259A IRQs without doing the
* quite slow i8259A_irq_real() call for every IRQ.
* This does not cover 100% of spurious interrupts,
* but should be enough to warn the user that there
* is something bad going on ...
*/
if (cached_irq_mask & irqmask)
goto spurious_8259A_irq;
cached_irq_mask |= irqmask;
handle_real_irq:
if (irq & 8) {
inb(0xA1); /* DUMMY - (do we need this?) */
outb(cached_A1,0xA1);
outb(0x60+(irq&7),0xA0);/* 'Specific EOI' to slave */
outb(0x62,0x20); /* 'Specific EOI' to master-IRQ2 */
} else {
inb(0x21); /* DUMMY - (do we need this?) */
outb(cached_21,0x21);
outb(0x60+irq,0x20); /* 'Specific EOI' to master */
}
spin_unlock_irqrestore(&i8259A_lock, flags);
return;
spurious_8259A_irq:
/*
* this is the slow path - should happen rarely.
*/
if (i8259A_irq_real(irq))
/*
* oops, the IRQ _is_ in service according to the
* 8259A - not spurious, go handle it.
*/
goto handle_real_irq;
{
static int spurious_irq_mask;
/*
* At this point we can be sure the IRQ is spurious,
* lets ACK and report it. [once per IRQ]
*/
if (!(spurious_irq_mask & irqmask)) {
printk("spurious 8259A interrupt: IRQ%d.\n", irq);
spurious_irq_mask |= irqmask;
}
atomic_inc(&irq_err_count);
/*
* Theoretically we do not have to handle this IRQ,
* but in Linux this does not cause problems and is
* simpler for us.
*/
goto handle_real_irq;
}
}
void __init init_8259A(int auto_eoi)
{
unsigned long flags;
spin_lock_irqsave(&i8259A_lock, flags);
outb(0xff, 0x21); /* mask all of 8259A-1 */
outb(0xff, 0xA1); /* mask all of 8259A-2 */
/*
* outb_p - this has to work on a wide range of PC hardware.
*/
outb_p(0x11, 0x20); /* ICW1: select 8259A-1 init */
outb_p(0x20 + 0, 0x21); /* ICW2: 8259A-1 IR0-7 mapped to 0x20-0x27 */
outb_p(0x04, 0x21); /* 8259A-1 (the master) has a slave on IR2 */
if (auto_eoi)
outb_p(0x03, 0x21); /* master does Auto EOI */
else
outb_p(0x01, 0x21); /* master expects normal EOI */
outb_p(0x11, 0xA0); /* ICW1: select 8259A-2 init */
outb_p(0x20 + 8, 0xA1); /* ICW2: 8259A-2 IR0-7 mapped to 0x28-0x2f */
outb_p(0x02, 0xA1); /* 8259A-2 is a slave on master's IR2 */
outb_p(0x01, 0xA1); /* (slave's support for AEOI in flat mode
is to be investigated) */
if (auto_eoi)
/*
* in AEOI mode we just have to mask the interrupt
* when acking.
*/
i8259A_irq_type.ack = disable_8259A_irq;
else
i8259A_irq_type.ack = mask_and_ack_8259A;
udelay(100); /* wait for 8259A to initialize */
outb(cached_21, 0x21); /* restore master IRQ mask */
outb(cached_A1, 0xA1); /* restore slave IRQ mask */
spin_unlock_irqrestore(&i8259A_lock, flags);
}
/*
* IRQ2 is cascade interrupt to second interrupt controller
*/
static struct irqaction irq2 = { no_action, 0, 0, "cascade", NULL, NULL};
void __init init_ISA_irqs (void)
{
int i;
#ifdef CONFIG_X86_LOCAL_APIC
init_bsp_APIC();
#endif
init_8259A(0);
for (i = 0; i < NR_IRQS; i++) {
irq_desc[i].status = IRQ_DISABLED;
irq_desc[i].action = 0;
irq_desc[i].depth = 1;
if (i < 16) {
/*
* 16 old-style INTA-cycle interrupts:
*/
irq_desc[i].handler = &i8259A_irq_type;
} else {
/*
* 'high' PCI IRQs filled in on demand
*/
irq_desc[i].handler = &no_irq_type;
}
}
}
void __init init_IRQ(void)
{
int i;
#ifndef CONFIG_X86_VISWS_APIC
init_ISA_irqs();
#else
init_VISWS_APIC_irqs();
#endif
/*
* Cover the whole vector space, no vector can escape
* us. (some of these will be overridden and become
* 'special' SMP interrupts)
*/
for (i = 0; i < NR_IRQS; i++) {
int vector = FIRST_EXTERNAL_VECTOR + i;
if (vector != IA32_SYSCALL_VECTOR) {
set_intr_gate(vector, interrupt[i]);
}
}
#ifdef CONFIG_SMP
/*
* IRQ0 must be given a fixed assignment and initialized,
* because it's used before the IO-APIC is set up.
*/
set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]);
/*
* The reschedule interrupt is a CPU-to-CPU reschedule-helper
* IPI, driven by wakeup.
*/
set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
/* IPI for invalidation */
set_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);
/* IPI for generic function call */
set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
#endif
#ifdef CONFIG_X86_LOCAL_APIC
/* self generated IPI for local APIC timer */
set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
/* IPI vectors for APIC spurious and error interrupts */
set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
set_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
#endif
#ifndef CONFIG_VISWS
if (!acpi_ioapic)
setup_irq(2, &irq2);
#endif
}