Move much closer to new platform-M memory map

[riscv-isa-sim.git] / riscv / mmu.cc

diff --git a/riscv/mmu.cc b/riscv/mmu.cc
index 6173b433cf0eeefec336f6df11437e20aaaa3360..0113443cfa4a83d92265ec7e91dccb5404212fd0 100644 (file)
--- a/riscv/mmu.cc
+++ b/riscv/mmu.cc
@@ -4,8 +4,8 @@
 #include "sim.h"
 #include "processor.h"
 
-mmu_t::mmu_t(char* _mem, size_t _memsz)
- : mem(_mem), memsz(_memsz), proc(NULL)
+mmu_t::mmu_t(sim_t* sim, processor_t* proc)
+ : sim(sim), proc(proc)
 {
   flush_tlb();
 }
@@ -34,9 +34,13 @@ reg_t mmu_t::translate(reg_t addr, access_type type)
   if (!proc)
     return addr;
 
-  reg_t mode = get_field(proc->state.mstatus, MSTATUS_PRV);
-  if (type != FETCH && get_field(proc->state.mstatus, MSTATUS_MPRV))
-    mode = get_field(proc->state.mstatus, MSTATUS_PRV1);
+  reg_t mode = proc->state.prv;
+  bool pum = false;
+  if (type != FETCH) {
+    if (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;
 
@@ -44,25 +48,32 @@ reg_t mmu_t::translate(reg_t addr, access_type type)
     reg_t msb_mask = (reg_t(2) << (proc->xlen-1))-1; // zero-extend from xlen
     return addr & msb_mask;
   }
-  return walk(addr, mode > PRV_U, type) | (addr & (PGSIZE-1));
+  return walk(addr, type, mode > PRV_U, pum) | (addr & (PGSIZE-1));
 }
 
 const uint16_t* mmu_t::fetch_slow_path(reg_t addr)
 {
   reg_t paddr = translate(addr, FETCH);
-  if (paddr >= memsz)
-    throw trap_instruction_access_fault(addr);
-  return (const uint16_t*)(mem + paddr);
+  if (sim->addr_is_mem(paddr)) {
+    refill_tlb(addr, paddr, FETCH);
+    return (const uint16_t*)sim->addr_to_mem(paddr);
+  } else {
+    if (!sim->mmio_load(paddr, sizeof fetch_temp, (uint8_t*)&fetch_temp))
+      throw trap_instruction_access_fault(addr);
+    return &fetch_temp;
+  }
 }
 
 void mmu_t::load_slow_path(reg_t addr, reg_t len, uint8_t* bytes)
 {
   reg_t paddr = translate(addr, LOAD);
-  if (paddr < memsz) {
-    memcpy(bytes, mem + paddr, len);
-    if (!tracer.interested_in_range(paddr, paddr + PGSIZE, LOAD))
+  if (sim->addr_is_mem(paddr)) {
+    memcpy(bytes, sim->addr_to_mem(paddr), len);
+    if (tracer.interested_in_range(paddr, paddr + PGSIZE, LOAD))
+      tracer.trace(paddr, len, LOAD);
+    else
       refill_tlb(addr, paddr, LOAD);
-  } else if (!proc || !proc->sim->mmio_load(addr, len, bytes)) {
+  } else if (!sim->mmio_load(paddr, len, bytes)) {
     throw trap_load_access_fault(addr);
   }
 }
@@ -70,11 +81,13 @@ void mmu_t::load_slow_path(reg_t addr, reg_t len, uint8_t* bytes)
 void mmu_t::store_slow_path(reg_t addr, reg_t len, const uint8_t* bytes)
 {
   reg_t paddr = translate(addr, STORE);
-  if (paddr < memsz) {
-    memcpy(mem + paddr, bytes, len);
-    if (!tracer.interested_in_range(paddr, paddr + PGSIZE, STORE))
+  if (sim->addr_is_mem(paddr)) {
+    memcpy(sim->addr_to_mem(paddr), bytes, len);
+    if (tracer.interested_in_range(paddr, paddr + PGSIZE, STORE))
+      tracer.trace(paddr, len, STORE);
+    else
       refill_tlb(addr, paddr, STORE);
-  } else if (!proc || !proc->sim->mmio_store(addr, len, bytes)) {
+  } else if (!sim->mmio_store(paddr, len, bytes)) {
     throw trap_store_access_fault(addr);
   }
 }
@@ -92,10 +105,10 @@ void mmu_t::refill_tlb(reg_t vaddr, reg_t paddr, access_type type)
   else if (type == STORE) tlb_store_tag[idx] = expected_tag;
   else tlb_load_tag[idx] = expected_tag;
 
-  tlb_data[idx] = mem + paddr - vaddr;
+  tlb_data[idx] = sim->addr_to_mem(paddr) - vaddr;
 }
 
-reg_t mmu_t::walk(reg_t addr, bool supervisor, access_type type)
+reg_t mmu_t::walk(reg_t addr, access_type type, bool supervisor, bool pum)
 {
   int levels, ptidxbits, ptesize;
   switch (get_field(proc->get_state()->mstatus, MSTATUS_VM))
@@ -113,22 +126,24 @@ reg_t mmu_t::walk(reg_t addr, bool supervisor, access_type type)
   if (masked_msbs != 0 && masked_msbs != mask)
     return -1;
 
-  reg_t base = proc->get_state()->sptbr;
+  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);
 
     // check that physical address of PTE is legal
     reg_t pte_addr = base + idx * ptesize;
-    if (pte_addr >= memsz)
+    if (!sim->addr_is_mem(pte_addr))
       break;
 
-    void* ppte = mem + pte_addr;
+    void* ppte = sim->addr_to_mem(pte_addr);
     reg_t pte = ptesize == 4 ? *(uint32_t*)ppte : *(uint64_t*)ppte;
     reg_t ppn = pte >> PTE_PPN_SHIFT;
 
     if (PTE_TABLE(pte)) { // next level of page table
       base = ppn << PGSHIFT;
+    } else if (pum && PTE_CHECK_PERM(pte, 0, type == STORE, type == FETCH)) {
+      break;
     } else if (!PTE_CHECK_PERM(pte, supervisor, type == STORE, type == FETCH)) {
       break;
     } else {