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/*=======================================================================================*/
/* This Sail RISC-V architecture model, comprising all files and */
/* directories except where otherwise noted is subject the BSD */
/* two-clause license in the LICENSE file. */
/* */
/* SPDX-License-Identifier: BSD-2-Clause */
/*=======================================================================================*/
// ****************************************************************
// PTW exceptions
// 'ext_ptw' supports (non-standard) extensions to the default addr-translation and PTW.
// See riscv_types_ext.sail for definitions.
// 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
}
// PRIVATE: only 'to_str' overload is public
function ptw_error_to_str(e : PTW_Error) -> string = {
match e {
PTW_Invalid_Addr() => "invalid-source-addr",
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",
PTW_Ext_Error(e) => "extension-error"
}
}
// PUBLIC
overload to_str = {ptw_error_to_str}
// hook for (non-standard) extensions to customize errors reported by page-table
// walks during address translation; it typically works in conjunction
// with any customization to check_PTE_permission().
// PRIVATE
function ext_get_ptw_error(eptwf : ext_ptw_fail) -> PTW_Error =
PTW_No_Permission()
// Convert translation/PTW failures into architectural exceptions
function translationException(a : AccessType(ext_access_type),
f : PTW_Error)
-> ExceptionType = {
match (a, f) {
(_, PTW_Ext_Error(e)) => E_Extension(ext_translate_exception(e)),
(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(),
(Execute(), PTW_Access()) => E_Fetch_Access_Fault(),
(Execute(), _) => E_Fetch_Page_Fault()
}
}
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