irq.c

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/*
 * kernel_arch/i386/kernel/irq.c
 *
 * Copyright (c) 2003-2004 Lukasz Dembinski <dembol@nasa.com.pl>
 * All Rights Reserved
 * 
 * Date:        2004/01
 * Author:      Lukasz Dembinski
 * Info:        irq.c core file
 * Contact:     mailto: <dembol@nasa.com.pl>
 *
 */
 
#include <agnix/agnix.h>
#include <asm/atomic.h>
#include <agnix/adi/adi.h>
#include <agnix/tasks.h>
#include <agnix/linkage.h>
#include <agnix/console.h>
#include <agnix/memory.h>
#include <agnix/irq.h>
#include <agnix/fastirq.h>
#include <asm/faults.h>
#include <agnix/list.h>
#include <agnix/sched.h>
#include <agnix/signals.h>
#include <agnix/fastrand.h>
#include <asm/segment.h>

#define __KERNEL_SYSCALLS__

asmlinkage void syscall_irq(struct regs_s regs);
asmlinkage void execute_irq(u32 irq, struct regs_s regs);

asmlinkage void IRQ_syscall(void);
    __asm__ (
    "\n.align 16,0x90\n"
    "IRQ_syscall:\n\t"
    REG_SAVE
    "call syscall_irq\n\t"
    REG_RESTORE
    "iret\n\t"
    );

#define IRQ_BUILD(nr,offset)            \
asmlinkage void IRQ_##nr##offset(void); \
    __asm__ (   \
    "\n.align 16,0x90\n"        \
    "IRQ_"#nr#offset":\n\t"     \
    REG_SAVE                    \
    "pushl $0x"#nr#offset"\n\t" \
    "call execute_irq\n\t"      \
    "addl $4, %esp\n\t"         \
    REG_RESTORE                 \
    "iret\n\t"                  \
    );

#define IRQ_BUILD_NAME(nr, offset)      \
    irq_names[nr * 16 + 0x##offset] = IRQ_##nr##offset;

#define IRQ_BUILD_16(x) \
    IRQ_BUILD(x,0); IRQ_BUILD(x,1); IRQ_BUILD(x,2); IRQ_BUILD(x,3);     \
    IRQ_BUILD(x,4); IRQ_BUILD(x,5); IRQ_BUILD(x,6); IRQ_BUILD(x,7);     \
    IRQ_BUILD(x,8); IRQ_BUILD(x,9); IRQ_BUILD(x,A); IRQ_BUILD(x,B);     \
    IRQ_BUILD(x,C); IRQ_BUILD(x,D); IRQ_BUILD(x,E); IRQ_BUILD(x,F);

#define IRQ_BUILD_NAME_16(x) \
    IRQ_BUILD_NAME(x,0); IRQ_BUILD_NAME(x,1); IRQ_BUILD_NAME(x,2); IRQ_BUILD_NAME(x,3); \
    IRQ_BUILD_NAME(x,4); IRQ_BUILD_NAME(x,5); IRQ_BUILD_NAME(x,6); IRQ_BUILD_NAME(x,7); \
    IRQ_BUILD_NAME(x,8); IRQ_BUILD_NAME(x,9); IRQ_BUILD_NAME(x,A); IRQ_BUILD_NAME(x,B); \
    IRQ_BUILD_NAME(x,C); IRQ_BUILD_NAME(x,D); IRQ_BUILD_NAME(x,E); IRQ_BUILD_NAME(x,F);

IRQ_BUILD_16(0);

extern struct chip_s i8259a_chip;
extern u32 random_val;

struct desc_struct idt_table[256] __attribute__((__section__("data.idt"))) = { {0, 0}, };
struct irq_s irq_info[256];
void (*irq_names[256])(void);
char irq_disabled[256];

void irq_disable_soft(u8 irq)
{
    atomic_write(&irq_disabled[irq], 1);
}

void irq_enable_soft(u8 irq)
{
    atomic_write(&irq_disabled[irq], 0);
}

asmlinkage void execute_irq(u32 irq, struct regs_s regs)
{
    struct chip_s *chip = &i8259a_chip;

    if (fastirq_started && (irq != 0))
        fastirq_queue(irq);
    else
        fastirq_run_irq(irq);

    pic_ops(chip)->ack_irq(chip, irq);

    if (current_task->signals.pending)
        execute_signals(current_task, &regs);

    //if ((regs.cs & 0x03) && current_task->t_resched) {
    if (current_task->t_resched) {
        schedule_task();
    }
}

int install_irq(u8 irq, struct irq_routine_s *irq_proc)
{
    struct chip_s *chip = &i8259a_chip;
    struct irq_s *irq_struct = &irq_info[irq];
    u32 flags;

    spin_lock_irqsave(&irq_struct->lock, flags);
    pic_ops(chip)->enable_irq(chip, irq);
    list_add(&irq_proc->list, &irq_struct->head);
    spin_unlock_irqrestore(&irq_struct->lock, flags);
    
    return 0;
}

int free_irq(u8 irq, struct irq_routine_s *irq_proc)
{
    struct chip_s *chip = &i8259a_chip;
    struct irq_s *irq_struct = &irq_info[irq];
    u32 flags;

    spin_lock_irqsave(&irq_struct->lock, flags);
    list_del(&irq_proc->list);

    if (list_empty(&irq_struct->head)) 
        pic_ops(chip)->disable_irq(chip, irq);

    spin_unlock_irqrestore(&irq_struct->lock, flags);

    return 0;
}

int __init irqs_init(void)
{
    int i;
    u32 flags;
    save_flags(flags); __cli();

    memset(irq_info, 0, 256 * sizeof(struct irq_s));

    for (i = 0; i < 256; i++) {
        INIT_LIST_HEAD(&irq_info[i].head);
        irq_disabled[i] = 0;
    }

    IRQ_BUILD_NAME_16(0);
    for (i = 0; i < 16; i++)
        set_interrupt_gate(32 + i, __KERNEL_CS, irq_names[i], 0);

    set_interrupt_gate(0x80, __KERNEL_CS, IRQ_syscall, 3);

    __asm__ __volatile__ ("lgdt %0" : "=m" (gdt_descr));
    __asm__ __volatile__ ("lidt %0" : "=m" (idt_descr));
    __asm__ __volatile__ ("pushfl ; andl $0xffffbfff, (%esp); popfl");

    restore_flags(flags);

    return 0;
}