From 39ed62d79e9f4ead6f52e755df9f9562e44696ac Mon Sep 17 00:00:00 2001 From: Prashanth Mundkur Date: Mon, 15 Jul 2019 11:07:56 -0700 Subject: Allow extensions to types of memory access, and factor out PTE and PTW definitions. --- model/riscv_vmem_common.sail | 89 -------------------------------------------- 1 file changed, 89 deletions(-) (limited to 'model/riscv_vmem_common.sail') diff --git a/model/riscv_vmem_common.sail b/model/riscv_vmem_common.sail index c8808f7..f77366b 100644 --- a/model/riscv_vmem_common.sail +++ b/model/riscv_vmem_common.sail @@ -8,95 +8,6 @@ let PAGESIZE_BITS = 12 -/* PTE attributes, permission checks and updates */ - -type pteAttribs = bits(8) - -bitfield PTE_Bits : pteAttribs = { - D : 7, - A : 6, - G : 5, - U : 4, - X : 3, - W : 2, - R : 1, - V : 0 -} - -function isPTEPtr(p : pteAttribs) -> bool = { - let a = Mk_PTE_Bits(p); - a.R() == false & a.W() == false & a.X() == false -} - -function isInvalidPTE(p : pteAttribs) -> bool = { - let a = Mk_PTE_Bits(p); - a.V() == false | (a.W() == true & a.R() == false) -} - -function checkPTEPermission(ac : AccessType, priv : Privilege, mxr : bool, do_sum : bool, p : PTE_Bits) -> bool = { - match (ac, priv) { - (Read, User) => p.U() == true & (p.R() == true | (p.X() == true & mxr)), - (Write, User) => p.U() == true & p.W() == true, - (ReadWrite, User) => p.U() == true & p.W() == true & (p.R() == true | (p.X() == true & mxr)), - (Execute, User) => p.U() == true & p.X() == true, - - (Read, Supervisor) => (p.U() == false | do_sum) & (p.R() == true | (p.X() == true & mxr)), - (Write, Supervisor) => (p.U() == false | do_sum) & p.W() == true, - (ReadWrite, Supervisor) => (p.U() == false | do_sum) & p.W() == true & (p.R() == true | (p.X() == true & mxr)), - (Execute, Supervisor) => p.U() == false & p.X() == true, - - (_, Machine) => internal_error("m-mode mem perm check") - } -} - -function update_PTE_Bits(p : PTE_Bits, a : AccessType) -> option(PTE_Bits) = { - let update_d = (a == Write | a == ReadWrite) & p.D() == false; // dirty-bit - let update_a = p.A() == false; // accessed-bit - if update_d | update_a then { - let np = update_A(p, true); - let np = if update_d then update_D(np, true) else np; - Some(np) - } else None() -} - -/* failure modes for address-translation/page-table-walks */ -enum PTW_Error = { - PTW_Access, /* physical memory access error for a PTE */ - PTW_Invalid_PTE, - PTW_No_Permission, - PTW_Misaligned, /* misaligned superpage */ - PTW_PTE_Update /* PTE update needed but not enabled */ -} -val ptw_error_to_str : PTW_Error -> string -function ptw_error_to_str(e) = - match (e) { - PTW_Access => "mem-access-error", - PTW_Invalid_PTE => "invalid-pte", - PTW_No_Permission => "no-permission", - PTW_Misaligned => "misaligned-superpage", - PTW_PTE_Update => "pte-update-needed" - } - -overload to_str = {ptw_error_to_str} - -/* conversion of these translation/PTW failures into architectural exceptions */ -function translationException(a : AccessType, f : PTW_Error) -> ExceptionType = { - let e : ExceptionType = - match (a, f) { - (ReadWrite, PTW_Access) => E_SAMO_Access_Fault, - (ReadWrite, _) => E_SAMO_Page_Fault, - (Read, PTW_Access) => E_Load_Access_Fault, - (Read, _) => E_Load_Page_Fault, - (Write, PTW_Access) => E_SAMO_Access_Fault, - (Write, _) => E_SAMO_Page_Fault, - (Fetch, PTW_Access) => E_Fetch_Access_Fault, - (Fetch, _) => E_Fetch_Page_Fault - } in { -/* print("translationException(" ^ a ^ ", " ^ f ^ ") -> " ^ e); */ - e - } -} - /* * Definitions for RV32, which has a single address translation mode: Sv32. */ -- cgit v1.1