1 /* This file contains routines for initializing the 8259 interrupt controller: 2 * put_irq_handler: register an interrupt handler 3 * rm_irq_handler: deregister an interrupt handler 4 * intr_handle: handle a hardware interrupt 5 * intr_init: initialize the interrupt controller(s) 6 */ 7 8 #include "kernel/kernel.h" 9 #include "arch_proto.h" 10 #include "hw_intr.h" 11 #include <minix/portio.h> 12 #include <machine/cpu.h> 13 14 #define ICW1_AT 0x11 /* edge triggered, cascade, need ICW4 */ 15 #define ICW1_PC 0x13 /* edge triggered, no cascade, need ICW4 */ 16 #define ICW1_PS 0x19 /* level triggered, cascade, need ICW4 */ 17 #define ICW4_AT_SLAVE 0x01 /* not SFNM, not buffered, normal EOI, 8086 */ 18 #define ICW4_AT_MASTER 0x05 /* not SFNM, not buffered, normal EOI, 8086 */ 19 #define ICW4_PC_SLAVE 0x09 /* not SFNM, buffered, normal EOI, 8086 */ 20 #define ICW4_PC_MASTER 0x0D /* not SFNM, buffered, normal EOI, 8086 */ 21 #define ICW4_AT_AEOI_SLAVE 0x03 /* not SFNM, not buffered, auto EOI, 8086 */ 22 #define ICW4_AT_AEOI_MASTER 0x07 /* not SFNM, not buffered, auto EOI, 8086 */ 23 #define ICW4_PC_AEOI_SLAVE 0x0B /* not SFNM, buffered, auto EOI, 8086 */ 24 #define ICW4_PC_AEOI_MASTER 0x0F /* not SFNM, buffered, auto EOI, 8086 */ 25 26 /*===========================================================================* 27 * intr_init * 28 *===========================================================================*/ 29 int intr_init(const int auto_eoi) 30 { 31 /* Initialize the 8259s, finishing with all interrupts disabled. */ 32 outb( INT_CTL, ICW1_AT); 33 outb( INT_CTLMASK, IRQ0_VECTOR); 34 /* ICW2 for master */ 35 outb( INT_CTLMASK, (1 << CASCADE_IRQ)); 36 /* ICW3 tells slaves */ 37 if (auto_eoi) 38 outb( INT_CTLMASK, ICW4_AT_AEOI_MASTER); 39 else 40 outb( INT_CTLMASK, ICW4_AT_MASTER); 41 outb( INT_CTLMASK, ~(1 << CASCADE_IRQ)); /* IRQ 0-7 mask */ 42 outb( INT2_CTL, ICW1_AT); 43 outb( INT2_CTLMASK, IRQ8_VECTOR); 44 /* ICW2 for slave */ 45 outb( INT2_CTLMASK, CASCADE_IRQ); /* ICW3 is slave nr */ 46 if (auto_eoi) 47 outb( INT2_CTLMASK, ICW4_AT_AEOI_SLAVE); 48 else 49 outb( INT2_CTLMASK, ICW4_AT_SLAVE); 50 outb( INT2_CTLMASK, ~0); /* IRQ 8-15 mask */ 51 52 return OK; 53 } 54 55 void irq_8259_unmask(const int irq) 56 { 57 const unsigned ctl_mask = irq < 8 ? INT_CTLMASK : INT2_CTLMASK; 58 outb(ctl_mask, inb(ctl_mask) & ~(1 << (irq & 0x7))); 59 } 60 61 void irq_8259_mask(const int irq) 62 { 63 const unsigned ctl_mask = irq < 8 ? INT_CTLMASK : INT2_CTLMASK; 64 outb(ctl_mask, inb(ctl_mask) | (1 << (irq & 0x7))); 65 } 66 67 /* Disable 8259 - write 0xFF in OCW1 master and slave. */ 68 void i8259_disable(void) 69 { 70 outb(INT2_CTLMASK, 0xFF); 71 outb(INT_CTLMASK, 0xFF); 72 inb(INT_CTLMASK); 73 } 74 75 void irq_8259_eoi(int irq) 76 { 77 if (irq < 8) 78 eoi_8259_master(); 79 else 80 eoi_8259_slave(); 81 } 82