xref: /titanic_50/usr/src/grub/grub-0.97/netboot/pic8259.h (revision 1b8adde7ba7d5e04395c141c5400dc2cffd7d809)
1*1b8adde7SWilliam Kucharski /*
2*1b8adde7SWilliam Kucharski  * Basic support for controlling the 8259 Programmable Interrupt Controllers.
3*1b8adde7SWilliam Kucharski  *
4*1b8adde7SWilliam Kucharski  * Initially written by Michael Brown (mcb30).
5*1b8adde7SWilliam Kucharski  */
6*1b8adde7SWilliam Kucharski 
7*1b8adde7SWilliam Kucharski #ifndef PIC8259_H
8*1b8adde7SWilliam Kucharski #define PIC8259_H
9*1b8adde7SWilliam Kucharski 
10*1b8adde7SWilliam Kucharski /* For segoff_t */
11*1b8adde7SWilliam Kucharski #include <segoff.h>
12*1b8adde7SWilliam Kucharski 
13*1b8adde7SWilliam Kucharski #define IRQ_PIC_CUTOFF (8)
14*1b8adde7SWilliam Kucharski 
15*1b8adde7SWilliam Kucharski /* 8259 register locations */
16*1b8adde7SWilliam Kucharski #define PIC1_ICW1 (0x20)
17*1b8adde7SWilliam Kucharski #define PIC1_OCW2 (0x20)
18*1b8adde7SWilliam Kucharski #define PIC1_OCW3 (0x20)
19*1b8adde7SWilliam Kucharski #define PIC1_ICR (0x20)
20*1b8adde7SWilliam Kucharski #define PIC1_IRR (0x20)
21*1b8adde7SWilliam Kucharski #define PIC1_ISR (0x20)
22*1b8adde7SWilliam Kucharski #define PIC1_ICW2 (0x21)
23*1b8adde7SWilliam Kucharski #define PIC1_ICW3 (0x21)
24*1b8adde7SWilliam Kucharski #define PIC1_ICW4 (0x21)
25*1b8adde7SWilliam Kucharski #define PIC1_IMR (0x21)
26*1b8adde7SWilliam Kucharski #define PIC2_ICW1 (0xa0)
27*1b8adde7SWilliam Kucharski #define PIC2_OCW2 (0xa0)
28*1b8adde7SWilliam Kucharski #define PIC2_OCW3 (0xa0)
29*1b8adde7SWilliam Kucharski #define PIC2_ICR (0xa0)
30*1b8adde7SWilliam Kucharski #define PIC2_IRR (0xa0)
31*1b8adde7SWilliam Kucharski #define PIC2_ISR (0xa0)
32*1b8adde7SWilliam Kucharski #define PIC2_ICW2 (0xa1)
33*1b8adde7SWilliam Kucharski #define PIC2_ICW3 (0xa1)
34*1b8adde7SWilliam Kucharski #define PIC2_ICW4 (0xa1)
35*1b8adde7SWilliam Kucharski #define PIC2_IMR (0xa1)
36*1b8adde7SWilliam Kucharski 
37*1b8adde7SWilliam Kucharski /* Register command values */
38*1b8adde7SWilliam Kucharski #define OCW3_ID (0x08)
39*1b8adde7SWilliam Kucharski #define OCW3_READ_IRR (0x03)
40*1b8adde7SWilliam Kucharski #define OCW3_READ_ISR (0x02)
41*1b8adde7SWilliam Kucharski #define ICR_EOI_NON_SPECIFIC (0x20)
42*1b8adde7SWilliam Kucharski #define ICR_EOI_NOP (0x40)
43*1b8adde7SWilliam Kucharski #define ICR_EOI_SPECIFIC (0x60)
44*1b8adde7SWilliam Kucharski #define ICR_EOI_SET_PRIORITY (0xc0)
45*1b8adde7SWilliam Kucharski 
46*1b8adde7SWilliam Kucharski /* Macros to enable/disable IRQs */
47*1b8adde7SWilliam Kucharski #define IMR_REG(x) ( (x) < IRQ_PIC_CUTOFF ? PIC1_IMR : PIC2_IMR )
48*1b8adde7SWilliam Kucharski #define IMR_BIT(x) ( 1 << ( (x) % IRQ_PIC_CUTOFF ) )
49*1b8adde7SWilliam Kucharski #define irq_enabled(x) ( ( inb ( IMR_REG(x) ) & IMR_BIT(x) ) == 0 )
50*1b8adde7SWilliam Kucharski #define enable_irq(x) outb ( inb( IMR_REG(x) ) & ~IMR_BIT(x), IMR_REG(x) )
51*1b8adde7SWilliam Kucharski #define disable_irq(x) outb ( inb( IMR_REG(x) ) | IMR_BIT(x), IMR_REG(x) )
52*1b8adde7SWilliam Kucharski 
53*1b8adde7SWilliam Kucharski /* Macros for acknowledging IRQs */
54*1b8adde7SWilliam Kucharski #define ICR_REG(x) ( (x) < IRQ_PIC_CUTOFF ? PIC1_ICR : PIC2_ICR )
55*1b8adde7SWilliam Kucharski #define ICR_VALUE(x) ( (x) % IRQ_PIC_CUTOFF )
56*1b8adde7SWilliam Kucharski #define CHAINED_IRQ 2
57*1b8adde7SWilliam Kucharski 
58*1b8adde7SWilliam Kucharski /* Utility macros to convert IRQ numbers to INT numbers and INT vectors  */
59*1b8adde7SWilliam Kucharski #define IRQ_INT(x) ( (x)<IRQ_PIC_CUTOFF ? (x)+0x08 : (x)-IRQ_PIC_CUTOFF+0x70 )
60*1b8adde7SWilliam Kucharski #define INT_VECTOR(x) ( (segoff_t*) phys_to_virt( 4 * (x) ) )
61*1b8adde7SWilliam Kucharski #define IRQ_VECTOR(x) ( INT_VECTOR ( IRQ_INT(x) ) )
62*1b8adde7SWilliam Kucharski 
63*1b8adde7SWilliam Kucharski /* Other constants */
64*1b8adde7SWilliam Kucharski typedef uint8_t irq_t;
65*1b8adde7SWilliam Kucharski #define IRQ_MAX (15)
66*1b8adde7SWilliam Kucharski #define IRQ_NONE (0xff)
67*1b8adde7SWilliam Kucharski 
68*1b8adde7SWilliam Kucharski /* Labels in assembly code (asm.S)
69*1b8adde7SWilliam Kucharski  */
70*1b8adde7SWilliam Kucharski extern void _undi_irq_handler_start;
71*1b8adde7SWilliam Kucharski extern void _undi_irq_handler ( void );
72*1b8adde7SWilliam Kucharski extern volatile uint16_t _undi_irq_trigger_count;
73*1b8adde7SWilliam Kucharski extern volatile uint16_t _undi_irq_fail_count;
74*1b8adde7SWilliam Kucharski extern volatile uint16_t _undi_irq_not_ours_count;
75*1b8adde7SWilliam Kucharski extern segoff_t _undi_irq_chain_to;
76*1b8adde7SWilliam Kucharski extern uint8_t _undi_irq_chain;
77*1b8adde7SWilliam Kucharski extern uint8_t _pxenv_undi_irq;
78*1b8adde7SWilliam Kucharski extern segoff_t _pxenv_undi_entrypointsp;
79*1b8adde7SWilliam Kucharski 
80*1b8adde7SWilliam Kucharski /* Function prototypes
81*1b8adde7SWilliam Kucharski  */
82*1b8adde7SWilliam Kucharski int install_irq_handler ( irq_t irq, segoff_t *handler,
83*1b8adde7SWilliam Kucharski 			  uint8_t *previously_enabled,
84*1b8adde7SWilliam Kucharski 			  segoff_t *previous_handler );
85*1b8adde7SWilliam Kucharski int remove_irq_handler ( irq_t irq, segoff_t *handler,
86*1b8adde7SWilliam Kucharski 			 uint8_t *previously_enabled,
87*1b8adde7SWilliam Kucharski 			 segoff_t *previous_handler );
88*1b8adde7SWilliam Kucharski int install_undi_irq_handler ( irq_t irq, segoff_t );
89*1b8adde7SWilliam Kucharski int remove_undi_irq_handler ( irq_t irq );
90*1b8adde7SWilliam Kucharski int undi_irq_triggered ( irq_t irq );
91*1b8adde7SWilliam Kucharski void send_specific_eoi ( irq_t irq );
92*1b8adde7SWilliam Kucharski #ifdef DEBUG_IRQ
93*1b8adde7SWilliam Kucharski void dump_irq_status ( void );
94*1b8adde7SWilliam Kucharski #else
95*1b8adde7SWilliam Kucharski #define dump_irq_status()
96*1b8adde7SWilliam Kucharski #endif
97*1b8adde7SWilliam Kucharski 
98*1b8adde7SWilliam Kucharski #endif /* PIC8259_H */
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