#define _RISCV_MMU_H
#include "decode.h"
+#include "icache.h"
#include "trap.h"
#include "common.h"
#include "config.h"
const reg_t PPN_BITS = 8*sizeof(reg_t) - PGSHIFT;
const reg_t VA_BITS = VPN_BITS + PGSHIFT;
+struct insn_fetch_t
+{
+ insn_func_t func;
+ union {
+ insn_t insn;
+ uint_fast32_t pad;
+ } insn;
+};
+
+struct icache_entry_t {
+ reg_t tag;
+ reg_t pad;
+ insn_fetch_t data;
+};
+
// this class implements a processor's port into the virtual memory system.
// an MMU and instruction cache are maintained for simulator performance.
class mmu_t
// template for functions that load an aligned value from memory
#define load_func(type) \
type##_t load_##type(reg_t addr) __attribute__((always_inline)) { \
- if(unlikely(addr % sizeof(type##_t))) \
- throw trap_load_address_misaligned(addr); \
void* paddr = translate(addr, sizeof(type##_t), false, false); \
return *(type##_t*)paddr; \
}
// template for functions that store an aligned value to memory
#define store_func(type) \
void store_##type(reg_t addr, type##_t val) { \
- if(unlikely(addr % sizeof(type##_t))) \
- throw trap_store_address_misaligned(addr); \
void* paddr = translate(addr, sizeof(type##_t), true, false); \
*(type##_t*)paddr = val; \
}
store_func(uint32)
store_func(uint64)
- struct insn_fetch_t
- {
- insn_func_t func;
- union {
- insn_t insn;
- uint_fast32_t pad;
- } insn;
- };
-
// load instruction from memory at aligned address.
- inline insn_fetch_t load_insn(reg_t addr)
+ inline icache_entry_t* access_icache(reg_t addr)
{
- reg_t offset = addr & (sizeof(insn_t) * (ICACHE_ENTRIES-1));
- offset *= sizeof(icache_entry_t) / sizeof(insn_t);
- icache_entry_t* entry = (icache_entry_t*)((char*)icache + offset);
- insn_fetch_t data = entry->data;
+ reg_t idx = (addr / sizeof(insn_t)) % ICACHE_SIZE;
+ icache_entry_t* entry = &icache[idx];
if (likely(entry->tag == addr))
- return data;
+ return entry;
void* iaddr = translate(addr, sizeof(insn_t), false, true);
insn_fetch_t fetch;
fetch.insn.pad = *(decltype(fetch.insn.insn.bits())*)iaddr;
fetch.func = proc->decode_insn(fetch.insn.insn);
- entry->tag = addr;
- entry->data = fetch;
+ icache[idx].tag = addr;
+ icache[idx].data = fetch;
reg_t paddr = (char*)iaddr - mem;
if (!tracer.empty() && tracer.interested_in_range(paddr, paddr + sizeof(insn_t), false, true))
{
- entry->tag = -1;
+ icache[idx].tag = -1;
tracer.trace(paddr, sizeof(insn_t), false, true);
}
- return entry->data;
+ return &icache[idx];
+ }
+
+ inline insn_fetch_t load_insn(reg_t addr)
+ {
+ return access_icache(addr)->data;
}
void set_processor(processor_t* p) { proc = p; flush_tlb(); }
memtracer_list_t tracer;
// implement an instruction cache for simulator performance
- static const reg_t ICACHE_ENTRIES = 2048;
- struct icache_entry_t {
- reg_t tag;
- reg_t pad;
- insn_fetch_t data;
- };
- icache_entry_t icache[ICACHE_ENTRIES];
+ icache_entry_t icache[ICACHE_SIZE];
// implement a TLB for simulator performance
static const reg_t TLB_ENTRIES = 256;
__attribute__((always_inline))
{
reg_t idx = (addr >> PGSHIFT) % TLB_ENTRIES;
- reg_t expected_tag = addr & ~(PGSIZE-1);
-
- reg_t* tlb_tag = fetch ? tlb_insn_tag : store ? tlb_store_tag :tlb_load_tag;
+ reg_t expected_tag = addr >> PGSHIFT;
+ reg_t* tags = fetch ? tlb_insn_tag : store ? tlb_store_tag :tlb_load_tag;
+ reg_t tag = tags[idx];
void* data = tlb_data[idx] + addr;
- if (likely(tlb_tag[idx] == expected_tag))
+
+ if (unlikely(addr & (bytes-1)))
+ store ? throw trap_store_address_misaligned(addr) : throw trap_load_address_misaligned(addr);
+
+ if (likely(tag == expected_tag))
return data;
return refill_tlb(addr, bytes, store, fetch);