if (!proc->state.dcsr.cause && get_field(proc->state.mstatus, MSTATUS_MPRV))
mode = get_field(proc->state.mstatus, MSTATUS_MPP);
}
- if (get_field(proc->state.mstatus, MSTATUS_VM) == VM_MBARE)
- mode = PRV_M;
- if (mode == PRV_M) {
- reg_t msb_mask = (reg_t(2) << (proc->xlen-1))-1; // zero-extend from xlen
- return addr & msb_mask;
- }
return walk(addr, type, mode) | (addr & (PGSIZE-1));
}
{
reg_t paddr = translate(vaddr, FETCH);
- // mmu_t::walk() returns -1 if it can't find a match. Of course -1 could also
- // be a valid address.
- if (paddr == ~(reg_t) 0 && vaddr != ~(reg_t) 0) {
- throw trap_instruction_access_fault(vaddr);
- }
-
if (sim->addr_is_mem(paddr)) {
refill_tlb(vaddr, paddr, FETCH);
return (const uint16_t*)sim->addr_to_mem(paddr);
reg_t mmu_t::walk(reg_t addr, access_type type, reg_t mode)
{
- int levels, ptidxbits, ptesize;
- switch (get_field(proc->get_state()->mstatus, MSTATUS_VM))
- {
- case VM_SV32: levels = 2; ptidxbits = 10; ptesize = 4; break;
- case VM_SV39: levels = 3; ptidxbits = 9; ptesize = 8; break;
- case VM_SV48: levels = 4; ptidxbits = 9; ptesize = 8; break;
- default: abort();
- }
+ vm_info vm = decode_vm_info(proc->max_xlen, mode, proc->get_state()->sptbr);
+ if (vm.levels == 0)
+ return addr & ((reg_t(2) << (proc->xlen-1))-1); // zero-extend from xlen
bool supervisor = mode == PRV_S;
bool pum = get_field(proc->state.mstatus, MSTATUS_PUM);
bool mxr = get_field(proc->state.mstatus, MSTATUS_MXR);
// verify bits xlen-1:va_bits-1 are all equal
- int va_bits = PGSHIFT + levels * ptidxbits;
+ int va_bits = PGSHIFT + vm.levels * vm.idxbits;
reg_t mask = (reg_t(1) << (proc->xlen - (va_bits-1))) - 1;
reg_t masked_msbs = (addr >> (va_bits-1)) & mask;
if (masked_msbs != 0 && masked_msbs != mask)
- return -1;
+ vm.levels = 0;
- reg_t base = proc->get_state()->sptbr << PGSHIFT;
- int ptshift = (levels - 1) * ptidxbits;
- for (int i = 0; i < levels; i++, ptshift -= ptidxbits) {
- reg_t idx = (addr >> (PGSHIFT + ptshift)) & ((1 << ptidxbits) - 1);
+ reg_t base = vm.ptbase;
+ for (int i = vm.levels - 1; i >= 0; i--) {
+ int ptshift = i * vm.idxbits;
+ reg_t idx = (addr >> (PGSHIFT + ptshift)) & ((1 << vm.idxbits) - 1);
// check that physical address of PTE is legal
- reg_t pte_addr = base + idx * ptesize;
+ reg_t pte_addr = base + idx * vm.ptesize;
if (!sim->addr_is_mem(pte_addr))
break;
void* ppte = sim->addr_to_mem(pte_addr);
- reg_t pte = ptesize == 4 ? *(uint32_t*)ppte : *(uint64_t*)ppte;
+ reg_t pte = vm.ptesize == 4 ? *(uint32_t*)ppte : *(uint64_t*)ppte;
reg_t ppn = pte >> PTE_PPN_SHIFT;
if (PTE_TABLE(pte)) { // next level of page table
}
}
- return -1;
+fail:
+ switch (type) {
+ case FETCH: throw trap_instruction_access_fault(addr);
+ case LOAD: throw trap_load_access_fault(addr);
+ case STORE: throw trap_store_access_fault(addr);
+ default: abort();
+ }
}
void mmu_t::register_memtracer(memtracer_t* t)