icache.c

#include "types.h"
#include "CPU.h"
#include "icache.h"

//#define ICACHE_DEBUGGING



#ifdef ICACHE_DEBUGGING
	#define _icache_fetch_func	icacheFetch_
	#define _icache_test_func	icacheFetch
#else
	#define _icache_fetch_func	icacheFetch
	#define _icache_test_func	icacheFetch_test
#endif

void icacheInval(icache* ic){

	UInt8 i, j;

	for(i = 0; i < ICACHE_BUCKET_NUM; i++){
		for(j = 0; j < ICACHE_BUCKET_SZ; j++) ic->lines[i][j].info = 0;
		ic->ptr[i] = 0;
	}
}

void icacheInit(icache* ic, ArmCpu* cpu, ArmCpuMemF memF){

	ic->cpu = cpu;
	ic->memF = memF;

	icacheInval(ic);
}


static UInt8 icachePrvHash(UInt32 addr){

	addr >>= ICACHE_L;
	addr &= (1UL << ICACHE_S) - 1UL;

	return addr;
}

void icacheInvalAddr(icache* ic, UInt32 va){

	UInt32 off = va % ICACHE_LINE_SZ;
	Int8 i, j, bucket;
	icacheLine* lines;

	va -= off;

	bucket = icachePrvHash(va);
	lines = ic->lines[bucket];

	for(i = 0, j = ic->ptr[bucket]; (UInt8)i < ICACHE_BUCKET_SZ; i++){

		if(--j == -1) j = ICACHE_BUCKET_SZ - 1;

		if((lines[j].info & (ICACHE_ADDR_MASK | ICACHE_USED_MASK)) == (va | ICACHE_USED_MASK)){	//found it!

			lines[j].info = 0;
		}
	}
}

/*
	we cannot have data overlap cachelines since data is self aligned (word on 4-byte boundary, halfwords on2, etc. this is enforced elsewhere
*/

Boolean _icache_fetch_func(icache* ic, UInt32 va, UInt8 sz, Boolean priviledged, UInt8* fsrP, void* buf){

	UInt32 off = va % ICACHE_LINE_SZ;
	Int8 i, j, bucket;
	icacheLine* lines;
	icacheLine* line;

	va -= off;

	bucket = icachePrvHash(va);
	lines = ic->lines[bucket];

	for(i = 0, j = ic->ptr[bucket]; (UInt8)i < ICACHE_BUCKET_SZ; i++){

		if(--j == -1) j = ICACHE_BUCKET_SZ - 1;

		if((lines[j].info & (ICACHE_ADDR_MASK | ICACHE_USED_MASK)) == (va | ICACHE_USED_MASK)){	//found it!

			if(sz == 4){
				*(UInt32*)buf = *(UInt32*)(lines[j].data + off);
			}
			else if(sz == 2){
#if BYTE_ORDER == LITTLE_ENDIAN
				*(UInt16*)buf = *(UInt16*)(lines[j].data + off);
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
#if BYTE_ORDER == BIG_ENDIAN
				if ((off % 4) == 0) {
					*(UInt16*)buf = *(UInt16*)(lines[j].data + off + 2);
				}
				else {
					*(UInt16*)buf = *(UInt16*)(lines[j].data + off - 2);
				}
#endif /* BYTE_ORDER == BIG_ENDIAN */
			}
			else __mem_copy(buf, lines[j].data + off, sz);
			return priviledged || !(lines[j].info & ICACHE_PRIV_MASK);
		}
	}
	//if we're here, we found nothing - time to populate the cache
	j = ic->ptr[bucket]++;
	if(ic->ptr[bucket] == ICACHE_BUCKET_SZ) ic->ptr[bucket] = 0;
	line = lines + j;

	line->info = va | (priviledged ? ICACHE_PRIV_MASK : 0);
	if(!ic->memF(ic->cpu, line->data, va, ICACHE_LINE_SZ, false, priviledged, fsrP)){

		return false;
	}
	line->info |= ICACHE_USED_MASK;

	if(sz == 4){
		*(UInt32*)buf = *(UInt32*)(line->data + off);
	}
	else if(sz == 2){
#if BYTE_ORDER == LITTLE_ENDIAN
		*(UInt16*)buf = *(UInt16*)(line->data + off);
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
#if BYTE_ORDER == BIG_ENDIAN
		if ((off % 4) == 0) {
			*(UInt16*)buf = *(UInt16*)(line->data + off + 2);
		}
		else {
			*(UInt16*)buf = *(UInt16*)(line->data + off - 2);
		}
#endif /* BYTE_ORDER == BIG_ENDIAN */
	}
	else __mem_copy(buf, line->data + off, sz);
	return true;
}

#include "stdio.h"
Boolean _icache_test_func(icache* ic, UInt32 va, UInt8 sz, Boolean priviledged, UInt8* fsrP, void* buf){

	UInt8 fsrO = -1, fsrT = -1;
	UInt8 dataO[4] = {0}, dataT[4] = {0};
	Boolean retO, retT;
	UInt8 i;

	retO = _icache_fetch_func(ic, va, sz, priviledged, &fsrO, dataO);
	retT = ic->memF(ic->cpu, dataT, va, sz, false, priviledged, &fsrT);

	if((retT != retO) || (fsrT != fsrO) || (dataT[0] != dataO[0]) || (dataT[1] != dataO[1]) || (dataT[2] != dataO[2]) || (dataT[3] != dataO[3])){

		fprintf(stderr, "icache fail!");
	}

	for(i = 0; i < sz; i++) ((UInt8*)buf)[i] = dataT[i];
	if(retT) *fsrP = fsrT;
	return retT;
}