minix/kernel/i8259.c
Jorrit Herder 198c976f7e System processes can be signaled; signals are transformed in SYS_EVENT message
that passes signal map along. This mechanisms is also used for nonuser signals
like SIGKMESS, SIGKSTOP, SIGKSIG.

Revised comments of many system call handlers. Renamed setpriority to nice.
2005-07-19 12:21:36 +00:00

194 lines
6.3 KiB
C
Executable file

/* This file contains routines for initializing the 8259 interrupt controller:
* put_irq_handler: register an interrupt handler
* rm_irq_handler: deregister an interrupt handler
* intr_handle: handle a hardware interrupt
* intr_init: initialize the interrupt controller(s)
*/
#include "kernel.h"
#include "proc.h"
#include <minix/com.h>
#define ICW1_AT 0x11 /* edge triggered, cascade, need ICW4 */
#define ICW1_PC 0x13 /* edge triggered, no cascade, need ICW4 */
#define ICW1_PS 0x19 /* level triggered, cascade, need ICW4 */
#define ICW4_AT_SLAVE 0x01 /* not SFNM, not buffered, normal EOI, 8086 */
#define ICW4_AT_MASTER 0x05 /* not SFNM, not buffered, normal EOI, 8086 */
#define ICW4_PC_SLAVE 0x09 /* not SFNM, buffered, normal EOI, 8086 */
#define ICW4_PC_MASTER 0x0D /* not SFNM, buffered, normal EOI, 8086 */
#if _WORD_SIZE == 2
typedef _PROTOTYPE( void (*vecaddr_t), (void) );
FORWARD _PROTOTYPE( void set_vec, (int vec_nr, vecaddr_t addr) );
PRIVATE vecaddr_t int_vec[] = {
int00, int01, int02, int03, int04, int05, int06, int07,
};
PRIVATE vecaddr_t irq_vec[] = {
hwint00, hwint01, hwint02, hwint03, hwint04, hwint05, hwint06, hwint07,
hwint08, hwint09, hwint10, hwint11, hwint12, hwint13, hwint14, hwint15,
};
#else
#define set_vec(nr, addr) ((void)0)
#endif
/*==========================================================================*
* intr_init *
*==========================================================================*/
PUBLIC void intr_init(mine)
int mine;
{
/* Initialize the 8259s, finishing with all interrupts disabled. This is
* only done in protected mode, in real mode we don't touch the 8259s, but
* use the BIOS locations instead. The flag "mine" is set if the 8259s are
* to be programmed for MINIX, or to be reset to what the BIOS expects.
*/
int i;
intr_disable();
if (machine.protected) {
/* The AT and newer PS/2 have two interrupt controllers, one master,
* one slaved at IRQ 2. (We don't have to deal with the PC that
* has just one controller, because it must run in real mode.)
*/
outb(INT_CTL, machine.ps_mca ? ICW1_PS : ICW1_AT);
outb(INT_CTLMASK, mine ? IRQ0_VECTOR : BIOS_IRQ0_VEC);
/* ICW2 for master */
outb(INT_CTLMASK, (1 << CASCADE_IRQ)); /* ICW3 tells slaves */
outb(INT_CTLMASK, ICW4_AT_MASTER);
outb(INT_CTLMASK, ~(1 << CASCADE_IRQ)); /* IRQ 0-7 mask */
outb(INT2_CTL, machine.ps_mca ? ICW1_PS : ICW1_AT);
outb(INT2_CTLMASK, mine ? IRQ8_VECTOR : BIOS_IRQ8_VEC);
/* ICW2 for slave */
outb(INT2_CTLMASK, CASCADE_IRQ); /* ICW3 is slave nr */
outb(INT2_CTLMASK, ICW4_AT_SLAVE);
outb(INT2_CTLMASK, ~0); /* IRQ 8-15 mask */
/* Copy the BIOS vectors from the BIOS to the Minix location, so we
* can still make BIOS calls without reprogramming the i8259s.
*/
#if IRQ0_VECTOR != BIOS_IRQ0_VEC
phys_copy(BIOS_VECTOR(0) * 4L, VECTOR(0) * 4L, 8 * 4L);
#endif
#if IRQ8_VECTOR != BIOS_IRQ8_VEC
phys_copy(BIOS_VECTOR(8) * 4L, VECTOR(8) * 4L, 8 * 4L);
#endif
} else {
/* Use the BIOS interrupt vectors in real mode. We only reprogram the
* exceptions here, the interrupt vectors are reprogrammed on demand.
* SYS_VECTOR is the Minix system call for message passing.
*/
for (i = 0; i < 8; i++) set_vec(i, int_vec[i]);
set_vec(SYS_VECTOR, s_call);
}
}
/*=========================================================================*
* put_irq_handler *
*=========================================================================*/
PUBLIC void put_irq_handler(hook, irq, handler)
irq_hook_t *hook;
int irq;
irq_handler_t handler;
{
/* Register an interrupt handler. */
int id;
irq_hook_t **line;
if (irq < 0 || irq >= NR_IRQ_VECTORS)
panic("invalid call to put_irq_handler", irq);
line = &irq_handlers[irq];
id = 1;
while (*line != NULL) {
if (hook == *line) return; /* extra initialization */
line = &(*line)->next;
id <<= 1;
}
if (id == 0) panic("Too many handlers for irq", irq);
hook->next = NULL;
hook->handler = handler;
hook->irq = irq;
hook->id = id;
*line = hook;
irq_use |= 1 << irq;
}
/*=========================================================================*
* rm_irq_handler *
*=========================================================================*/
PUBLIC int rm_irq_handler(irq, id)
int irq;
int id;
{
/* Unregister an interrupt handler. */
irq_hook_t **line;
if (irq < 0 || irq >= NR_IRQ_VECTORS) return(EINVAL);
line = &irq_handlers[irq];
while (*line != NULL) {
if((*line)->id == id) {
(*line) = (*line)->next;
if(! irq_handlers[irq])
irq_use &= ~(1 << irq);
return(OK);
}
line = &(*line)->next;
}
return(ENOENT);
}
/*==========================================================================*
* intr_handle *
*==========================================================================*/
PUBLIC void intr_handle(hook)
irq_hook_t *hook;
{
/* Call the interrupt handlers for an interrupt with the given hook list.
* The assembly part of the handler has already masked the IRQ, reenabled the
* controller(s) and enabled interrupts.
*/
/* Call list of handlers for an IRQ. */
while (hook != NULL) {
/* For each handler in the list, mark it active by setting its ID bit,
* call the function, and unmark it if the function returns true.
*/
irq_actids[hook->irq] |= hook->id;
if ((*hook->handler)(hook)) irq_actids[hook->irq] &= ~hook->id;
hook = hook->next;
}
/* The assembly code will now disable interrupts, unmask the IRQ if and only
* if all active ID bits are cleared, and restart a process.
*/
}
#if _WORD_SIZE == 2
/*===========================================================================*
* set_vec *
*===========================================================================*/
PRIVATE void set_vec(vec_nr, addr)
int vec_nr; /* which vector */
vecaddr_t addr; /* where to start */
{
/* Set up a real mode interrupt vector. */
u16_t vec[2];
/* Build the vector in the array 'vec'. */
vec[0] = (u16_t) addr;
vec[1] = (u16_t) physb_to_hclick(code_base);
/* Copy the vector into place. */
phys_copy(vir2phys(vec), vec_nr * 4L, 4L);
}
#endif /* _WORD_SIZE == 2 */