#include <linux/linkage.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/init.h>
#include <linux/kernel_stat.h>
#include <linux/sysdev.h>
#include <linux/bitops.h>
#include <asm/acpi.h>
#include <asm/atomic.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/hw_irq.h>
#include <asm/pgtable.h>
#include <asm/delay.h>
#include <asm/desc.h>
#include <asm/apic.h>
/*
* 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 0x30-0x3f)
*/
/*
* 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(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) BUILD_16_IRQS(0xe) BUILD_16_IRQS(0xf)
#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)
/* for the irq vectors */
static void (*interrupt[NR_VECTORS - FIRST_EXTERNAL_VECTOR])(void) = {
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), IRQLIST_16(0xe), IRQLIST_16(0xf)
};
#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
*/
static int i8259A_auto_eoi;
DEFINE_SPINLOCK(i8259A_lock);
static void mask_and_ack_8259A(unsigned int);
static struct irq_chip i8259A_chip = {
.name = "XT-PIC",
.mask = disable_8259A_irq,
.disable = disable_8259A_irq,
.unmask = enable_8259A_irq,
.mask_ack = mask_and_ack_8259A,
};
/*
* 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);
set_irq_chip_and_handler_name(irq, &i8259A_chip, handle_level_irq,
"XT");
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!
*/
static 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 unnecessarily.
*
* 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(KERN_DEBUG "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_8259A(int auto_eoi)
{
unsigned long flags;
i8259A_auto_eoi = auto_eoi;
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(IRQ0_VECTOR, 0x21); /* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 */
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(IRQ8_VECTOR, 0xA1); /* ICW2: 8259A-2 IR0-7 mapped to 0x38-0x3f */
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_chip.mask_ack = disable_8259A_irq;
else
i8259A_chip.mask_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);
}
static char irq_trigger[2];
/**
* ELCR registers (0x4d0, 0x4d1) control edge/level of IRQ
*/
static void restore_ELCR(char *trigger)
{
outb(trigger[0], 0x4d0);
outb(trigger[1], 0x4d1);
}
static void save_ELCR(char *trigger)
{
/* IRQ 0,1,2,8,13 are marked as reserved */
trigger[0] = inb(0x4d0) & 0xF8;
trigger[1] = inb(0x4d1) & 0xDE;
}
static int i8259A_resume(struct sys_device *dev)
{
init_8259A(i8259A_auto_eoi);
restore_ELCR(irq_trigger);
return 0;
}
static int i8259A_suspend(struct sys_device *dev, pm_message_t state)
{
save_ELCR(irq_trigger);
return 0;
}
static int i8259A_shutdown(struct sys_device *dev)
{
/* Put the i8259A into a quiescent state that
* the kernel initialization code can get it
* out of.
*/
outb(0xff, 0x21); /* mask all of 8259A-1 */
outb(0xff, 0xA1); /* mask all of 8259A-1 */
return 0;
}
static struct sysdev_class i8259_sysdev_class = {
set_kset_name("i8259"),
.suspend = i8259A_suspend,
.resume = i8259A_resume,
.shutdown = i8259A_shutdown,
};
static struct sys_device device_i8259A = {
.id = 0,
.cls = &i8259_sysdev_class,
};
static int __init i8259A_init_sysfs(void)
{
int error = sysdev_class_register(&i8259_sysdev_class);
if (!error)
error = sysdev_register(&device_i8259A);
return error;
}
device_initcall(i8259A_init_sysfs);
/*
* IRQ2 is cascade interrupt to second interrupt controller
*/
static struct irqaction irq2 = {
.handler = no_action,
.mask = CPU_MASK_NONE,
.name = "cascade",
};
DEFINE_PER_CPU(vector_irq_t, vector_irq) = {
[0 ... IRQ0_VECTOR - 1] = -1,
[IRQ0_VECTOR] = 0,
[IRQ1_VECTOR] = 1,
[IRQ2_VECTOR] = 2,
[IRQ3_VECTOR] = 3,
[IRQ4_VECTOR] = 4,
[IRQ5_VECTOR] = 5,
[IRQ6_VECTOR] = 6,
[IRQ7_VECTOR] = 7,
[IRQ8_VECTOR] = 8,
[IRQ9_VECTOR] = 9,
[IRQ10_VECTOR] = 10,
[IRQ11_VECTOR] = 11,
[IRQ12_VECTOR] = 12,
[IRQ13_VECTOR] = 13,
[IRQ14_VECTOR] = 14,
[IRQ15_VECTOR] = 15,
[IRQ15_VECTOR + 1 ... NR_VECTORS - 1] = -1
};
void __init init_ISA_irqs (void)
{
int i;
init_bsp_APIC();
init_8259A(0);
for (i = 0; i < NR_IRQS; i++) {
irq_desc[i].status = IRQ_DISABLED;
irq_desc[i].action = NULL;
irq_desc[i].depth = 1;
if (i < 16) {
/*
* 16 old-style INTA-cycle interrupts:
*/
set_irq_chip_and_handler_name(i, &i8259A_chip,
handle_level_irq, "XT");
} else {
/*
* 'high' PCI IRQs filled in on demand
*/
irq_desc[i].chip = &no_irq_chip;
}
}
}
void __init init_IRQ(void)
{
int i;
init_ISA_irqs();
/*
* 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_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
int vector = FIRST_EXTERNAL_VECTOR + i;
if (vector != IA32_SYSCALL_VECTOR)
set_intr_gate(vector, interrupt[i]);
}
#ifdef CONFIG_SMP
/*
* The reschedule interrupt is a CPU-to-CPU reschedule-helper
* IPI, driven by wakeup.
*/
set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
/* IPIs for invalidation */
set_intr_gate(INVALIDATE_TLB_VECTOR_START+0, invalidate_interrupt0);
set_intr_gate(INVALIDATE_TLB_VECTOR_START+1, invalidate_interrupt1);
set_intr_gate(INVALIDATE_TLB_VECTOR_START+2, invalidate_interrupt2);
set_intr_gate(INVALIDATE_TLB_VECTOR_START+3, invalidate_interrupt3);
set_intr_gate(INVALIDATE_TLB_VECTOR_START+4, invalidate_interrupt4);
set_intr_gate(INVALIDATE_TLB_VECTOR_START+5, invalidate_interrupt5);
set_intr_gate(INVALIDATE_TLB_VECTOR_START+6, invalidate_interrupt6);
set_intr_gate(INVALIDATE_TLB_VECTOR_START+7, invalidate_interrupt7);
/* IPI for generic function call */
set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);
/* Low priority IPI to cleanup after moving an irq */
set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt);
#endif
set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
set_intr_gate(THRESHOLD_APIC_VECTOR, threshold_interrupt);
/* 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);
if (!acpi_ioapic)
setup_irq(2, &irq2);
}
