return addr;
reg_t mode = proc->state.prv;
- bool pum = false;
if (type != FETCH) {
if (!proc->state.dcsr.cause && get_field(proc->state.mstatus, MSTATUS_MPRV))
mode = get_field(proc->state.mstatus, MSTATUS_MPP);
- pum = (mode == PRV_S && get_field(proc->state.mstatus, MSTATUS_PUM));
}
if (get_field(proc->state.mstatus, MSTATUS_VM) == VM_MBARE)
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 > PRV_U, pum) | (addr & (PGSIZE-1));
+ return walk(addr, type, mode) | (addr & (PGSIZE-1));
}
const uint16_t* mmu_t::fetch_slow_path(reg_t vaddr)
tlb_data[idx] = sim->addr_to_mem(paddr) - vaddr;
}
-reg_t mmu_t::walk(reg_t addr, access_type type, bool supervisor, bool pum)
+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))
default: abort();
}
+ 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;
reg_t mask = (reg_t(1) << (proc->xlen - (va_bits-1))) - 1;
if (PTE_TABLE(pte)) { // next level of page table
base = ppn << PGSHIFT;
- } else if (pum && PTE_CHECK_PERM(pte, 0, type == STORE, type == FETCH)) {
+ } else if ((pte & PTE_U) ? supervisor && pum : !supervisor) {
+ break;
+ } else if (!(pte & PTE_R) && (pte & PTE_W)) { // reserved
break;
- } else if (!PTE_CHECK_PERM(pte, supervisor, type == STORE, type == FETCH)) {
+ } else if (type == FETCH ? !(pte & PTE_X) :
+ type == LOAD ? !(pte & PTE_R) && !(mxr && (pte & PTE_X)) :
+ !((pte & PTE_R) && (pte & PTE_W))) {
break;
} else {
- // set referenced and possibly dirty bits.
- *(uint32_t*)ppte |= PTE_R | ((type == STORE) * PTE_D);
+ // set accessed and possibly dirty bits.
+ *(uint32_t*)ppte |= PTE_A | ((type == STORE) * PTE_D);
// for superpage mappings, make a fake leaf PTE for the TLB's benefit.
reg_t vpn = addr >> PGSHIFT;
reg_t value = (ppn | (vpn & ((reg_t(1) << ptshift) - 1))) << PGSHIFT;