// Copyright 2020 The gVisor Authors. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. //go:build arm64 // +build arm64 package pagetables // limitPCID is the maximum value of PCIDs. // // In VMSAv8-64, the PCID(ASID) size is an IMPLEMENTATION DEFINED choice // of 8 bits or 16 bits, and ID_AA64MMFR0_EL1.ASIDBits identifies the // supported size. When an implementation supports a 16-bit ASID, TCR_ELx.AS // selects whether the top 8 bits of the ASID are used. var limitPCID uint16 // GetASIDBits return the system ASID bits, 8 or 16 bits. func GetASIDBits() uint8 func init() { limitPCID = uint16(1)<<GetASIDBits() - 1 }