linux/arch/x86/include/asm/i8259.h
Jacob Pan ef3548668c x86, pic: Introduce legacy_pic abstraction
This patch makes i8259A like legacy programmable interrupt controller
code into a driver so that legacy pic functions can be selected at
runtime based on platform information, such as HW subarchitecure ID.
Default structure of legacy_pic maintains the current code path for
x86pc.

Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
LKML-Reference: <43F901BD926A4E43B106BF17856F07559FB80D03@orsmsx508.amr.corp.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-02-19 16:25:17 -08:00

76 lines
1.9 KiB
C

#ifndef _ASM_X86_I8259_H
#define _ASM_X86_I8259_H
#include <linux/delay.h>
extern unsigned int cached_irq_mask;
#define __byte(x, y) (((unsigned char *)&(y))[x])
#define cached_master_mask (__byte(0, cached_irq_mask))
#define cached_slave_mask (__byte(1, cached_irq_mask))
/* i8259A PIC registers */
#define PIC_MASTER_CMD 0x20
#define PIC_MASTER_IMR 0x21
#define PIC_MASTER_ISR PIC_MASTER_CMD
#define PIC_MASTER_POLL PIC_MASTER_ISR
#define PIC_MASTER_OCW3 PIC_MASTER_ISR
#define PIC_SLAVE_CMD 0xa0
#define PIC_SLAVE_IMR 0xa1
/* i8259A PIC related value */
#define PIC_CASCADE_IR 2
#define MASTER_ICW4_DEFAULT 0x01
#define SLAVE_ICW4_DEFAULT 0x01
#define PIC_ICW4_AEOI 2
extern spinlock_t i8259A_lock;
extern void init_8259A(int auto_eoi);
extern void enable_8259A_irq(unsigned int irq);
extern void disable_8259A_irq(unsigned int irq);
extern unsigned int startup_8259A_irq(unsigned int irq);
/* the PIC may need a careful delay on some platforms, hence specific calls */
static inline unsigned char inb_pic(unsigned int port)
{
unsigned char value = inb(port);
/*
* delay for some accesses to PIC on motherboard or in chipset
* must be at least one microsecond, so be safe here:
*/
udelay(2);
return value;
}
static inline void outb_pic(unsigned char value, unsigned int port)
{
outb(value, port);
/*
* delay for some accesses to PIC on motherboard or in chipset
* must be at least one microsecond, so be safe here:
*/
udelay(2);
}
extern struct irq_chip i8259A_chip;
struct legacy_pic {
int nr_legacy_irqs;
struct irq_chip *chip;
void (*mask_all)(void);
void (*restore_mask)(void);
void (*init)(int auto_eoi);
int (*irq_pending)(unsigned int irq);
void (*make_irq)(unsigned int irq);
};
extern struct legacy_pic *legacy_pic;
extern struct legacy_pic null_legacy_pic;
extern void mask_8259A(void);
extern void unmask_8259A(void);
#endif /* _ASM_X86_I8259_H */