#include
#include
#include
#include
#include “armemu.h”
void cache_init(struct cache_st *csp) {
if (csp->type == CT_DIRECT_MAPPED) {
csp->ways = 1;
csp->index_mask = (csp->size) – 1;
} else if (csp->type == CT_SET_ASSOCIATIVE) {
// TODO
}
csp->index_bits = 0;
while (csp->index_mask & (1 << csp->index_bits)) {
csp->index_bits++;
}
for (int i = 0; i < CACHE_MAX_SLOTS; i++) {
csp->slots[i].valid = 0;
csp->slots[i].tag = 0;
csp->slots[i].data = 0;
// timestamp only used for SA cache
csp->slots[i].timestamp = 0;
}
csp->refs = 0;
csp->hits = 0;
csp->misses = 0;
csp->misses_cold = 0;
csp->misses_hot = 0;
}
void cache_print(struct cache_st *csp) {
int num_slots_used = 0;
int i;
for (i = 0; i < csp->size; i++) {
if (csp->slots[i].valid == 1) {
num_slots_used += 1;
}
}
printf(“=== Cache\n”);
printf(“Type = “);
if (csp->type == CT_DIRECT_MAPPED) {
printf(“direct mapped\n”);
} else if (csp->type == CT_SET_ASSOCIATIVE) {
printf(“4-way set associative\n”);
}
printf(“Size = %d slots\n”, csp->size);
printf(“References = %d\n”, csp->refs);
printf(“Hits = %d (%.2f%% hit ratio)\n”, csp->hits,
((double) csp->hits / (double) csp->refs) * 100.00);
printf(“Misses = %d (%.2f%% miss ratio)\n”, csp->misses,
((double) csp->misses / (double) csp->refs) * 100.00);
printf(“Misses (cold) = %d\n”, csp->misses_cold);
printf(“Misses (hot) = %d\n”, csp->misses_hot);
printf(“%% Used = %.2f%%\n”, ((double) num_slots_used / (double) csp->size) * 100.0);
}
// Direct mapped lookup
uint32_t cache_lookup_dm(struct cache_st *csp, uint32_t addr) {
uint32_t tag;
uint32_t index;
struct cache_slot_st *slot;
uint32_t data;
index = (addr >> 2) & csp->index_mask;
tag = addr >> (csp->index_bits + 2);
slot = &csp->slots[index];
csp->refs += 1;
if (slot->valid && (slot->tag == tag)) {
// hit
csp->hits += 1;
data = slot->data;
verbose(” cache tag hit for index %d tag %X addr %lX\n”,
index, tag, addr);
} else {
// miss
csp->misses += 1;
if (slot->valid == 0) {
csp->misses_cold += 1;
verbose(” cache tag (%X) miss for index %d tag %X addr %X (cold)\n”,
slot->tag, index, tag, addr);
} else {
csp->misses_hot += 1;
verbose(” cache tag (%X) miss for index %d tag %X addr %X (hot)\n”,
slot->tag, index, tag, addr);
}
slot->valid = 1;
slot->tag = tag;
data = *((uint32_t *) addr);
slot->data = data;
}
return data;
}
uint32_t cache_lookup_sa(struct cache_st *csp, uint32_t addr) {
// TODO
return 0;
}
// Cache lookup
uint32_t cache_lookup(struct cache_st *csp, uint32_t addr) {
uint32_t data;
if (csp->type == CT_DIRECT_MAPPED) {
data = cache_lookup_dm(csp, addr);
} else if (csp->type == CT_SET_ASSOCIATIVE) {
data = cache_lookup_sa(csp, addr);
} else {
data = *((uint32_t *) addr);
}
return data;
}