diff options
Diffstat (limited to 'model/riscv_vmem_sv48.sail')
-rw-r--r-- | model/riscv_vmem_sv48.sail | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/model/riscv_vmem_sv48.sail b/model/riscv_vmem_sv48.sail new file mode 100644 index 0000000..b29ae52 --- /dev/null +++ b/model/riscv_vmem_sv48.sail @@ -0,0 +1,106 @@ +/* Sv48 address translation for RV64. */ + +val walk48 : (vaddr48, AccessType, Privilege, bool, bool, paddr64, nat, bool) -> PTW_Result(paddr64, SV48_PTE) effect {rmem, escape} +function walk48(vaddr, ac, priv, mxr, do_sum, ptb, level, global) = { + let va = Mk_SV48_Vaddr(vaddr); + let pt_ofs : paddr64 = shiftl(EXTZ(shiftr(va.VPNi(), (level * SV48_LEVEL_BITS))[(SV48_LEVEL_BITS - 1) .. 0]), + PTE48_LOG_SIZE); + let pte_addr = ptb + pt_ofs; + /* FIXME: we assume here that walks only access physical-memory-backed addresses, and not MMIO regions. */ + match (phys_mem_read(Data, EXTZ(pte_addr), 8, false, false, false)) { + MemException(_) => { +/* print("walk48(vaddr=" ^ BitStr(vaddr) ^ " level=" ^ string_of_int(level) + ^ " pt_base=" ^ BitStr(ptb) + ^ " pt_ofs=" ^ BitStr(pt_ofs) + ^ " pte_addr=" ^ BitStr(pte_addr) + ^ ": invalid pte address"); */ + PTW_Failure(PTW_Access) + }, + MemValue(v) => { + let pte = Mk_SV48_PTE(v); + let pbits = pte.BITS(); + let pattr = Mk_PTE_Bits(pbits); + let is_global = global | (pattr.G() == true); +/* print("walk48(vaddr=" ^ BitStr(vaddr) ^ " level=" ^ string_of_int(level) + ^ " pt_base=" ^ BitStr(ptb) + ^ " pt_ofs=" ^ BitStr(pt_ofs) + ^ " pte_addr=" ^ BitStr(pte_addr) + ^ " pte=" ^ BitStr(v)); */ + if isInvalidPTE(pbits) then { +/* print("walk48: invalid pte"); */ + PTW_Failure(PTW_Invalid_PTE) + } else { + if isPTEPtr(pbits) then { + if level == 0 then { + /* last-level PTE contains a pointer instead of a leaf */ +/* print("walk48: last-level pte contains a ptr"); */ + PTW_Failure(PTW_Invalid_PTE) + } else { + /* walk down the pointer to the next level */ + walk48(vaddr, ac, priv, mxr, do_sum, EXTZ(shiftl(pte.PPNi(), PAGESIZE_BITS)), level - 1, is_global) + } + } else { /* leaf PTE */ + if ~ (checkPTEPermission(ac, priv, mxr, do_sum, pattr)) then { +/* print("walk48: pte permission check failure"); */ + PTW_Failure(PTW_No_Permission) + } else { + if level > 0 then { /* superpage */ + /* fixme hack: to get a mask of appropriate size */ + let mask = shiftl(pte.PPNi() ^ pte.PPNi() ^ EXTZ(0b1), level * SV48_LEVEL_BITS) - 1; + if (pte.PPNi() & mask) != EXTZ(0b0) then { + /* misaligned superpage mapping */ +/* print("walk48: misaligned superpage mapping"); */ + PTW_Failure(PTW_Misaligned) + } else { + /* add the appropriate bits of the VPN to the superpage PPN */ + let ppn = pte.PPNi() | (EXTZ(va.VPNi()) & mask); +/* let res = append(ppn, va.PgOfs()); + print("walk48: using superpage: pte.ppn=" ^ BitStr(pte.PPNi()) + ^ " ppn=" ^ BitStr(ppn) ^ " res=" ^ BitStr(res)); */ + PTW_Success(append(ppn, va.PgOfs()), pte, pte_addr, level, is_global) + } + } else { + /* normal leaf PTE */ +/* let res = append(pte.PPNi(), va.PgOfs()); + print("walk48: pte.ppn=" ^ BitStr(pte.PPNi()) ^ " ppn=" ^ BitStr(pte.PPNi()) ^ " res=" ^ BitStr(res)); */ + PTW_Success(append(pte.PPNi(), va.PgOfs()), pte, pte_addr, level, is_global) + } + } + } + } + } + } +} + +val translate48 : (asid64, paddr64, vaddr48, AccessType, Privilege, bool, bool, nat) -> TR_Result(paddr64, PTW_Error) effect {rreg, wreg, wmv, escape, rmem} +function translate48(asid, ptb, vAddr, ac, priv, mxr, do_sum, level) = { + match walk48(vAddr, ac, priv, mxr, do_sum, ptb, level, false) { + PTW_Failure(f) => TR_Failure(f), + PTW_Success(pAddr, pte, pteAddr, level, global) => { + match update_PTE_Bits(Mk_PTE_Bits(pte.BITS()), ac) { + None() => { + /* addToTLB48(asid, vAddr, pAddr, pte, pteAddr, level, global); */ + TR_Address(pAddr) + }, + Some(pbits) => + if ~ (plat_enable_dirty_update ()) + then { + /* pte needs dirty/accessed update but that is not enabled */ + TR_Failure(PTW_PTE_Update) + } else { + w_pte : SV48_PTE = update_BITS(pte, pbits.bits()); + match checked_mem_write(EXTZ(pteAddr), 8, w_pte.bits(), false, false, false) { + MemValue(_) => { + /* addToTLB48(asid, vAddr, pAddr, w_pte, pteAddr, level, global); */ + TR_Address(pAddr) + }, + MemException(e) => { + /* pte is not in valid memory */ + TR_Failure(PTW_Access) + } + } + } + } + } + } +} |