#include "sim_interrupts.h"
#include "sim_core.h"
+// modulo a cursor value on the pending interrupt fifo
+#define INT_FIFO_SIZE (sizeof(avr->pending) / sizeof(avr_int_vector_t *))
+#define INT_FIFO_MOD(_v) ((_v) & (INT_FIFO_SIZE - 1))
+
void avr_register_vector(avr_t *avr, avr_int_vector_t * vector)
{
if (vector->vector) {
vector->irq.irq = vector->vector;
- avr->vector[vector->vector] = vector;
+ avr->vector[avr->vector_count++] = vector;
if (vector->trace)
printf("%s register vector %d (enabled %04x:%d)\n", __FUNCTION__, vector->vector, vector->enable.reg, vector->enable.bit);
int avr_has_pending_interrupts(avr_t * avr)
{
- return avr->pending[0] || avr->pending[1];
+ return avr->pending_r != avr->pending_w;
}
int avr_is_interrupt_pending(avr_t * avr, avr_int_vector_t * vector)
{
- return avr->pending[vector->vector >> 5] & (1 << (vector->vector & 0x1f));
+ return vector->pending;
}
int avr_is_interrupt_enabled(avr_t * avr, avr_int_vector_t * vector)
return 0;
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 "pooling" for the "raised" flag, like for non-interrupt
// driven UART and so so. These flags are often "write one to clear"
avr_regbit_set(avr, vector->raised);
// Mark the interrupt as pending
- avr->pending[vector->vector >> 5] |= (1 << (vector->vector & 0x1f));
+ vector->pending = 1;
+ avr->pending[avr->pending_w++] = vector;
+ avr->pending_w = INT_FIFO_MOD(avr->pending_w);
+
avr_raise_irq(&vector->irq, 1);
// If the interrupt is enabled, attempt to wake the core
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;
if (vector->trace)
printf("%s cleared %d\n", __FUNCTION__, vector->vector);
+ vector->pending = 0;
avr_raise_irq(&vector->irq, 0);
if (vector->raised.reg)
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->vector);
+ avr_clear_interrupt(avr, vector);
avr_regbit_clear(avr, vector->raised);
return 1;
}
avr_irq_t * avr_get_interrupt_irq(avr_t * avr, uint8_t v)
{
- avr_int_vector_t * vector = avr->vector[v];
- return vector ? &vector->irq : NULL;
+ for (int i = 0; i < avr->vector_count; i++)
+ if (avr->vector[i]->vector == v)
+ return &avr->vector[i]->irq;
+ return NULL;
}
/*
if (!avr->sreg[S_I])
return;
- if (avr_has_pending_interrupts(avr)) {
- if (avr->pending_wait) {
- avr->pending_wait--;
- if (avr->pending_wait == 0) {
- for (int bi = 0; bi < 2; bi++)
- if (avr->pending[bi]) {
- uint32_t map = avr->pending[bi];
- while (map) {
- int bit = ffs(map)-1;
- int v = (bi * 32) + bit; // vector
- avr_int_vector_t * vector = avr->vector[v];
- // if that single interrupt is masked, ignore it and continue
- if (vector && !avr_regbit_get(avr, vector->enable)) {
- map &= ~(1 << bit);
- continue;
- }
- if (vector && vector->trace)
- 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);
- break;
- }
- break;
- }
- }
- } else
- avr->pending_wait = 2; // for next one...
+ if (!avr_has_pending_interrupts(avr))
+ return;
+
+ if (!avr->pending_wait) {
+ avr->pending_wait = 2; // for next one...
+ return;
+ }
+ avr->pending_wait--;
+ if (avr->pending_wait)
+ return;
+
+ // how many are pending...
+ int cnt = avr->pending_w > avr->pending_r ?
+ avr->pending_w - avr->pending_r :
+ (avr->pending_w+INT_FIFO_SIZE) - avr->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(avr->pending_r + ii);
+ avr_int_vector_t * v = avr->pending[vi];
+ if (v->vector < min) {
+ min = v->vector;
+ mini = vi;
+ }
+ }
+ avr_int_vector_t * vector = avr->pending[mini];
+
+ // now move the one at the front of the fifo in the slot of
+ // the one we service
+ avr->pending[mini] = avr->pending[avr->pending_r++];
+ avr->pending_r = INT_FIFO_MOD(avr->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