#ifndef __irq_h
#define __irq_h

#include <asm/irq.h>

/*
 * Interrupt controller descriptor. This is all we need
 * to describe about the low-level hardware.
 */
struct hw_interrupt_type {
	const char * typename;
	void (*startup)(unsigned int irq);
	void (*shutdown)(unsigned int irq);
	void (*handle)(unsigned int irq, struct pt_regs * regs);
	void (*enable)(unsigned int irq);
	void (*disable)(unsigned int irq);
};

extern struct hw_interrupt_type no_irq_type;

/*
 * IRQ line status.
 */
#define IRQ_INPROGRESS	1	/* IRQ handler active - do not enter! */
#define IRQ_DISABLED	2	/* IRQ disabled - do not enter! */
#define IRQ_PENDING	4	/* IRQ pending - replay on enable */
#define IRQ_REPLAY	8	/* IRQ has been replayed but not acked yet */
#define IRQ_AUTODETECT	16	/* IRQ is being autodetected */
#define IRQ_WAITING	32	/* IRQ not yet seen - for autodetection */

/*
 * This is the "IRQ descriptor", which contains various information
 * about the irq, including what kind of hardware handling it has,
 * whether it is disabled etc etc.
 *
 * Pad this out to 32 bytes for cache and indexing reasons.
 */
typedef struct {
	unsigned int status;			/* IRQ status - IRQ_INPROGRESS, IRQ_DISABLED */
	struct hw_interrupt_type *handler;	/* handle/enable/disable functions */
	struct irqaction *action;		/* IRQ action list */
	unsigned int depth;			/* Disable depth for nested irq disables */
} irq_desc_t;

/*
 * IDT vectors usable for external interrupt sources start
 * at 0x20:
 */
#define FIRST_EXTERNAL_VECTOR	0x20

#define SYSCALL_VECTOR		0x80

/*
 * Vectors 0x20-0x2f are used for ISA interrupts.
 */

/*
 * Special IRQ vectors used by the SMP architecture:
 *
 * (some of the following vectors are 'rare', they might be merged
 *  into a single vector to save vector space. TLB, reschedule and
 *  local APIC vectors are performance-critical.)
 */
#define RESCHEDULE_VECTOR	0x30
#define INVALIDATE_TLB_VECTOR	0x31
#define STOP_CPU_VECTOR		0x40
#define LOCAL_TIMER_VECTOR	0x41
#define CALL_FUNCTION_VECTOR	0x50

/*
 * First APIC vector available to drivers: (vectors 0x51-0xfe)
 */
#define IRQ0_TRAP_VECTOR	0x51

/*
 * This IRQ should never happen, but we print a message nevertheless.
 */
#define SPURIOUS_APIC_VECTOR	0xff

extern irq_desc_t irq_desc[NR_IRQS];
extern int irq_vector[NR_IRQS];
#define IO_APIC_VECTOR(irq)	irq_vector[irq]

extern void init_IRQ_SMP(void);
extern int handle_IRQ_event(unsigned int, struct pt_regs *, struct irqaction *);
extern int setup_x86_irq(unsigned int, struct irqaction *);

/*
 * Various low-level irq details needed by irq.c, process.c,
 * time.c, io_apic.c and smp.c
 *
 * Interrupt entry/exit code at both C and assembly level
 */

extern void no_action(int cpl, void *dev_id, struct pt_regs *regs);
extern void mask_irq(unsigned int irq);
extern void unmask_irq(unsigned int irq);
extern void disable_8259A_irq(unsigned int irq);
extern int i8259A_irq_pending(unsigned int irq);
extern void ack_APIC_irq(void);
extern void FASTCALL(send_IPI_self(int vector));
extern void init_VISWS_APIC_irqs(void);
extern void setup_IO_APIC(void);
extern int IO_APIC_get_PCI_irq_vector(int bus, int slot, int fn);
extern void make_8259A_irq(unsigned int irq);
extern void send_IPI(int dest, int vector);
extern void init_pic_mode(void);
extern void print_IO_APIC(void);

extern unsigned long io_apic_irqs;

extern char _stext, _etext;

#define MAX_IRQ_SOURCES 128
#define MAX_MP_BUSSES 32
enum mp_bustype {
	MP_BUS_ISA,
	MP_BUS_EISA,
	MP_BUS_PCI
};
extern int mp_bus_id_to_type [MAX_MP_BUSSES];
extern int mp_bus_id_to_pci_bus [MAX_MP_BUSSES];
extern char ioapic_OEM_ID [16];
extern char ioapic_Product_ID [16];

extern spinlock_t irq_controller_lock;

#ifdef __SMP__

#include <asm/atomic.h>

static inline void irq_enter(int cpu, unsigned int irq)
{
	hardirq_enter(cpu);
	while (test_bit(0,&global_irq_lock)) {
		/* nothing */;
	}
}

static inline void irq_exit(int cpu, unsigned int irq)
{
	hardirq_exit(cpu);
}

#define IO_APIC_IRQ(x) (((x) >= 16) || ((1<<(x)) & io_apic_irqs))

#else

#define irq_enter(cpu, irq)	(++local_irq_count[cpu])
#define irq_exit(cpu, irq)	(--local_irq_count[cpu])

#define IO_APIC_IRQ(x)	(0)

#endif

#define __STR(x) #x
#define STR(x) __STR(x)

#define SAVE_ALL \
	"cld\n\t" \
	"pushl %es\n\t" \
	"pushl %ds\n\t" \
	"pushl %eax\n\t" \
	"pushl %ebp\n\t" \
	"pushl %edi\n\t" \
	"pushl %esi\n\t" \
	"pushl %edx\n\t" \
	"pushl %ecx\n\t" \
	"pushl %ebx\n\t" \
	"movl $" STR(__KERNEL_DS) ",%edx\n\t" \
	"movl %dx,%ds\n\t" \
	"movl %dx,%es\n\t"

#define IRQ_NAME2(nr) nr##_interrupt(void)
#define IRQ_NAME(nr) IRQ_NAME2(IRQ##nr)

#define GET_CURRENT \
	"movl %esp, %ebx\n\t" \
	"andl $-8192, %ebx\n\t"

#ifdef __SMP__

/*
 *	SMP has a few special interrupts for IPI messages
 */

#define BUILD_SMP_INTERRUPT(x) \
asmlinkage void x(void); \
__asm__( \
"\n"__ALIGN_STR"\n" \
SYMBOL_NAME_STR(x) ":\n\t" \
	"pushl $-1\n\t" \
	SAVE_ALL \
	"call "SYMBOL_NAME_STR(smp_##x)"\n\t" \
	"jmp ret_from_intr\n");

#define BUILD_SMP_TIMER_INTERRUPT(x) \
asmlinkage void x(struct pt_regs * regs); \
__asm__( \
"\n"__ALIGN_STR"\n" \
SYMBOL_NAME_STR(x) ":\n\t" \
	"pushl $-1\n\t" \
	SAVE_ALL \
	"movl %esp,%eax\n\t" \
	"pushl %eax\n\t" \
	"call "SYMBOL_NAME_STR(smp_##x)"\n\t" \
	"addl $4,%esp\n\t" \
	"jmp ret_from_intr\n");

#endif /* __SMP__ */

#define BUILD_COMMON_IRQ() \
__asm__( \
	"\n" __ALIGN_STR"\n" \
	"common_interrupt:\n\t" \
	SAVE_ALL \
	"pushl $ret_from_intr\n\t" \
	"jmp "SYMBOL_NAME_STR(do_IRQ));

/*
 * subtle. orig_eax is used by the signal code to distinct between
 * system calls and interrupted 'random user-space'. Thus we have
 * to put a negative value into orig_eax here. (the problem is that
 * both system calls and IRQs want to have small integer numbers in
 * orig_eax, and the syscall code has won the optimization conflict ;)
 */
#define BUILD_IRQ(nr) \
asmlinkage void IRQ_NAME(nr); \
__asm__( \
"\n"__ALIGN_STR"\n" \
SYMBOL_NAME_STR(IRQ) #nr "_interrupt:\n\t" \
	"pushl $"#nr"-256\n\t" \
	"jmp common_interrupt");

/*
 * x86 profiling function, SMP safe. We might want to do this in
 * assembly totally?
 */
static inline void x86_do_profile (unsigned long eip)
{
	if (prof_buffer && current->pid) {
		eip -= (unsigned long) &_stext;
		eip >>= prof_shift;
		/*
		 * Don't ignore out-of-bounds EIP values silently,
		 * put them into the last histogram slot, so if
		 * present, they will show up as a sharp peak.
		 */
		if (eip > prof_len-1)
			eip = prof_len-1;
		atomic_inc((atomic_t *)&prof_buffer[eip]);
	}
}

#endif