Add svnapot extention support

model/riscv_vmem.sail

@@ -164,7 +164,30 @@ function pt_walk(sv_params,
  }
  }
  else {
+ let mask_bits = level * sv_params.pte_PPN_j_size_bits;
+ let mask : bits(64) = ~ (ones() << mask_bits);
+ let ppn : bits(64) = ppns | (vpns_of_va(sv_params, va) & mask);
+ let napot_mask : bits(64) = ppn ^ (ppn - 1);
+ let napot_mask_not : bits(64) = ~ (napot_mask);
+ let ptshift_level = sv_params.levels - 1;
+ let ptshift = ptshift_level * sv_params.vpn_size_bits;
+
+ let page_base = (ppn & napot_mask_not) | 
+ (vpns_of_va(sv_params, va) & napot_mask) | 
+ (vpns_of_va(sv_params, va) & ((zero_extend(0b1) << ptshift) - zero_extend(0b1)));
+
  let pa = (ppns << pagesize_bits) | zero_extend(offset_of_va(va));
+ let pa_napot = page_base << 12 | zero_extend(offset_of_va(va));
+
+ // For svnapot ext purpose.
+ if (pte & (zero_extend(0b1) << 63)) == (zero_extend(0b1) << 63) then {
+ if (napot_mask != zero_extend(0xf)) then {
+ return PTW_Failure(PTW_Invalid_PTE(), ext_ptw)
+ } else {
+ return PTW_Success(pa_napot, pte, pte_addr, level, global', ext_ptw)
+ }
+ };
+
  PTW_Success(pa, pte, pte_addr, level, global', ext_ptw)
  }
  }

model/riscv_vmem_ptw.sail

@@ -15,13 +15,14 @@
 // Failure modes for address-translation/page-table-walks
 // PRIVATE
 union PTW_Error = {
- PTW_Invalid_Addr : unit, // invalid source address
- PTW_Access : unit, // physical memory access error for a PTE
- PTW_Invalid_PTE : unit,
- PTW_No_Permission : unit,
- PTW_Misaligned : unit, // misaligned superpage
- PTW_PTE_Update : unit, // PTE update needed but not enabled
- PTW_Ext_Error : ext_ptw_error // parameterized for errors from extensions
+ PTW_Invalid_Addr : unit, // invalid source address
+ PTW_Access : unit, // physical memory access error for a PTE
+ PTW_Invalid_PTE : unit,
+ PTW_No_Permission : unit,
+ PTW_Misaligned : unit, // misaligned superpage
+ PTW_PTE_Update : unit, // PTE update needed but not enabled
+ PTW_Ext_Error : ext_ptw_error, // parameterized for errors from extensions
+ PTW_Unsupport_Napot : unit // Unsupport Napot bits
 }
 
 // PRIVATE: only 'to_str' overload is public
@@ -33,7 +34,8 @@ function ptw_error_to_str(e : PTW_Error) -> string = {
  PTW_No_Permission() => "no-permission",
  PTW_Misaligned() => "misaligned-superpage",
  PTW_PTE_Update() => "pte-update-needed",
- PTW_Ext_Error(e) => "extension-error"
+ PTW_Ext_Error(e) => "extension-error",
+ PTW_Unsupport_Napot()=> "unsupport napot bits"
  }
 }