/*
sim_interrupts.c
- Copyright 2008, 2009 Michel Pollet <buserror@gmail.com>
+ Copyright 2008-2012 Michel Pollet <buserror@gmail.com>
This file is part of simavr.
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
+#include <strings.h>
#include "sim_interrupts.h"
+#include "sim_avr.h"
#include "sim_core.h"
-void avr_register_vector(avr_t *avr, avr_int_vector_t * vector)
+// modulo a cursor value on the pending interrupt fifo
+#define INT_FIFO_SIZE (sizeof(table->pending) / sizeof(avr_int_vector_t *))
+#define INT_FIFO_MOD(_v) ((_v) & (INT_FIFO_SIZE - 1))
+
+void
+avr_interrupt_reset(
+ avr_t * avr )
+{
+ avr_int_table_p table = &avr->interrupts;
+ memset(table, 0, sizeof(*table));
+}
+
+void
+avr_register_vector(
+ avr_t *avr,
+ avr_int_vector_t * vector)
+{
+ if (!vector->vector)
+ return;
+
+ avr_int_table_p table = &avr->interrupts;
+
+ vector->irq.irq = vector->vector;
+ table->vector[table->vector_count++] = vector;
+ if (vector->trace)
+ printf("%s register vector %d (enabled %04x:%d)\n", __FUNCTION__, vector->vector, vector->enable.reg, vector->enable.bit);
+
+ if (!vector->enable.reg)
+ AVR_LOG(avr, LOG_WARNING, "INT: avr_register_vector: No 'enable' bit on vector %d !\n", vector->vector);
+}
+
+int
+avr_has_pending_interrupts(
+ avr_t * avr)
{
- if (vector->vector)
- avr->vector[vector->vector] = vector;
+ avr_int_table_p table = &avr->interrupts;
+ return table->pending_r != table->pending_w;
}
-int avr_has_pending_interrupts(avr_t * avr)
+int
+avr_is_interrupt_pending(
+ avr_t * avr,
+ avr_int_vector_t * vector)
{
- return avr->pending[0] || avr->pending[1];
+ return vector->pending;
}
-int avr_is_interrupt_pending(avr_t * avr, avr_int_vector_t * vector)
+int
+avr_is_interrupt_enabled(
+ avr_t * avr,
+ avr_int_vector_t * vector)
{
- return avr->pending[vector->vector >> 5] & (1 << (vector->vector & 0x1f));
+ return avr_regbit_get(avr, vector->enable);
}
-int avr_raise_interrupt(avr_t * avr, avr_int_vector_t * vector)
+int
+avr_raise_interrupt(
+ avr_t * avr,
+ avr_int_vector_t * vector)
{
if (!vector || !vector->vector)
return 0;
-// printf("%s raising %d\n", __FUNCTION__, vector->vector);
- // always mark the 'raised' flag to one, even if the interuot is disabled
- // this allow "pooling" for the "raised" flag, like for non-interrupt
+ if (vector->trace)
+ printf("%s raising %d (enabled %d)\n", __FUNCTION__, vector->vector, avr_regbit_get(avr, vector->enable));
+ if (vector->pending) {
+ if (vector->trace)
+ printf("%s trying to double raise %d (enabled %d)\n", __FUNCTION__, vector->vector, avr_regbit_get(avr, vector->enable));
+ return 0;
+ }
+ // always mark the 'raised' flag to one, even if the interrupt is disabled
+ // this allow "polling" for the "raised" flag, like for non-interrupt
// driven UART and so so. These flags are often "write one to clear"
if (vector->raised.reg)
avr_regbit_set(avr, vector->raised);
- if (vector->enable.reg) {
- if (!avr_regbit_get(avr, vector->enable))
- return 0;
- }
- if (!avr_is_interrupt_pending(avr, vector)) {
- if (!avr->pending_wait)
- avr->pending_wait = 2; // latency on interrupts ??
- avr->pending[vector->vector >> 5] |= (1 << (vector->vector & 0x1f));
- if (avr->state != cpu_Running) {
- // printf("Waking CPU due to interrupt\n");
+ avr_raise_irq(&vector->irq, 1);
+
+ // If the interrupt is enabled, attempt to wake the core
+ if (avr_regbit_get(avr, vector->enable)) {
+ // Mark the interrupt as pending
+ vector->pending = 1;
+
+ avr_int_table_p table = &avr->interrupts;
+
+ table->pending[table->pending_w++] = vector;
+ table->pending_w = INT_FIFO_MOD(table->pending_w);
+
+ if (!table->pending_wait)
+ table->pending_wait = 1; // latency on interrupts ??
+ if (avr->state == cpu_Sleeping) {
+ if (vector->trace)
+ printf("Waking CPU due to interrupt\n");
avr->state = cpu_Running; // in case we were sleeping
}
}
return 1;
}
-void avr_clear_interrupt(avr_t * avr, int v)
+void
+avr_clear_interrupt(
+ avr_t * avr,
+ avr_int_vector_t * vector)
{
- avr_int_vector_t * vector = avr->vector[v];
- avr->pending[v >> 5] &= ~(1 << (v & 0x1f));
if (!vector)
return;
- printf("%s cleared %d\n", __FUNCTION__, vector->vector);
- if (vector->raised.reg)
+ if (vector->trace)
+ printf("%s cleared %d\n", __FUNCTION__, vector->vector);
+ vector->pending = 0;
+ avr_raise_irq(&vector->irq, 0);
+ if (vector->raised.reg && !vector->raise_sticky)
avr_regbit_clear(avr, vector->raised);
}
+int
+avr_clear_interrupt_if(
+ avr_t * avr,
+ avr_int_vector_t * vector,
+ uint8_t old)
+{
+ if (avr_regbit_get(avr, vector->raised)) {
+ avr_clear_interrupt(avr, vector);
+ return 1;
+ }
+ avr_regbit_setto(avr, vector->raised, old);
+ return 0;
+}
+
+avr_irq_t *
+avr_get_interrupt_irq(
+ avr_t * avr,
+ uint8_t v)
+{
+ avr_int_table_p table = &avr->interrupts;
+ for (int i = 0; i < table->vector_count; i++)
+ if (table->vector[i]->vector == v)
+ return &table->vector[i]->irq;
+ return NULL;
+}
+
/*
- * check wether interrupts are pending. I so, check if the interrupt "latency" is reached,
+ * check whether interrupts are pending. If so, check if the interrupt "latency" is reached,
* and if so triggers the handlers and jump to the vector.
*/
-void avr_service_interrupts(avr_t * avr)
+void
+avr_service_interrupts(
+ avr_t * avr)
{
if (!avr->sreg[S_I])
return;
- if (avr_has_pending_interrupts(avr)) {
- if (avr->pending_wait) {
- avr->pending_wait--;
- if (avr->pending_wait == 0) {
- int done = 0;
- for (int bi = 0; bi < 2 && !done; bi++) if (avr->pending[bi]) {
- for (int ii = 0; ii < 32 && !done; ii++)
- if (avr->pending[bi] & (1 << ii)) {
-
- int v = (bi * 32) + ii; // vector
-
- // printf("%s calling %d\n", __FUNCTION__, v);
- _avr_push16(avr, avr->pc >> 1);
- avr->sreg[S_I] = 0;
- avr->pc = v * avr->vector_size;
-
- avr_clear_interrupt(avr, v);
- done++;
- break;
- }
- break;
- }
- }
- } else
- avr->pending_wait = 2; // for next one...
+ if (!avr_has_pending_interrupts(avr))
+ return;
+
+ avr_int_table_p table = &avr->interrupts;
+
+ if (!table->pending_wait) {
+ table->pending_wait = 2; // for next one...
+ return;
+ }
+ table->pending_wait--;
+ if (table->pending_wait)
+ return;
+
+ // how many are pending...
+ int cnt = table->pending_w > table->pending_r ?
+ table->pending_w - table->pending_r :
+ (table->pending_w + INT_FIFO_SIZE) - table->pending_r;
+ // locate the highest priority one
+ int min = 0xff;
+ int mini = 0;
+ for (int ii = 0; ii < cnt; ii++) {
+ int vi = INT_FIFO_MOD(table->pending_r + ii);
+ avr_int_vector_t * v = table->pending[vi];
+ if (v->vector < min) {
+ min = v->vector;
+ mini = vi;
+ }
+ }
+ avr_int_vector_t * vector = table->pending[mini];
+
+ // now move the one at the front of the fifo in the slot of
+ // the one we service
+ table->pending[mini] = table->pending[table->pending_r++];
+ table->pending_r = INT_FIFO_MOD(table->pending_r);
+
+ // if that single interrupt is masked, ignore it and continue
+ // could also have been disabled, or cleared
+ if (!avr_regbit_get(avr, vector->enable) || !vector->pending) {
+ vector->pending = 0;
+ } else {
+ if (vector && vector->trace)
+ printf("%s calling %d\n", __FUNCTION__, (int)vector->vector);
+ _avr_push16(avr, avr->pc >> 1);
+ avr->sreg[S_I] = 0;
+ avr->pc = vector->vector * avr->vector_size;
+
+ avr_clear_interrupt(avr, vector);
}
}
projects / simavr / blobdiff