LXR linux/arch/x86/include/asm/i8259.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_X86_I8259_H
   3#define _ASM_X86_I8259_H
   4
   5#include <linux/delay.h>
   6
   7extern unsigned int cached_irq_mask;
   8
   9#define __byte(x, y)            (((unsigned char *)&(y))[x])
  10#define cached_master_mask      (__byte(0, cached_irq_mask))
  11#define cached_slave_mask       (__byte(1, cached_irq_mask))
  12
  13/* i8259A PIC registers */
  14#define PIC_MASTER_CMD          0x20
  15#define PIC_MASTER_IMR          0x21
  16#define PIC_MASTER_ISR          PIC_MASTER_CMD
  17#define PIC_MASTER_POLL         PIC_MASTER_ISR
  18#define PIC_MASTER_OCW3         PIC_MASTER_ISR
  19#define PIC_SLAVE_CMD           0xa0
  20#define PIC_SLAVE_IMR           0xa1
  21
  22/* i8259A PIC related value */
  23#define PIC_CASCADE_IR          2
  24#define MASTER_ICW4_DEFAULT     0x01
  25#define SLAVE_ICW4_DEFAULT      0x01
  26#define PIC_ICW4_AEOI           2
  27
  28extern raw_spinlock_t i8259A_lock;
  29
  30/* the PIC may need a careful delay on some platforms, hence specific calls */
  31static inline unsigned char inb_pic(unsigned int port)
  32{
  33        unsigned char value = inb(port);
  34
  35        /*
  36         * delay for some accesses to PIC on motherboard or in chipset
  37         * must be at least one microsecond, so be safe here:
  38         */
  39        udelay(2);
  40
  41        return value;
  42}
  43
  44static inline void outb_pic(unsigned char value, unsigned int port)
  45{
  46        outb(value, port);
  47        /*
  48         * delay for some accesses to PIC on motherboard or in chipset
  49         * must be at least one microsecond, so be safe here:
  50         */
  51        udelay(2);
  52}
  53
  54extern struct irq_chip i8259A_chip;
  55
  56struct legacy_pic {
  57        int nr_legacy_irqs;
  58        struct irq_chip *chip;
  59        void (*mask)(unsigned int irq);
  60        void (*unmask)(unsigned int irq);
  61        void (*mask_all)(void);
  62        void (*restore_mask)(void);
  63        void (*init)(int auto_eoi);
  64        int (*probe)(void);
  65        int (*irq_pending)(unsigned int irq);
  66        void (*make_irq)(unsigned int irq);
  67};
  68
  69extern struct legacy_pic *legacy_pic;
  70extern struct legacy_pic null_legacy_pic;
  71
  72static inline bool has_legacy_pic(void)
  73{
  74        return legacy_pic != &null_legacy_pic;
  75}
  76
  77static inline int nr_legacy_irqs(void)
  78{
  79        return legacy_pic->nr_legacy_irqs;
  80}
  81
  82#endif /* _ASM_X86_I8259_H */
  83