From a7083ece990adddfd3bec8b48c5db7dee1781d55 Mon Sep 17 00:00:00 2001 From: Giacomo Travaglini Date: Thu, 15 Feb 2018 09:57:00 +0000 Subject: arch-arm: Adding isa templates for semihosting ops A new class of Semihosting constructor templates has been added. Their main purpose is to check if the Exception Generation Instructions (HLT, SVC) are actually a semihosting command. If that is the case, the IsMemBarrier flag is raised, so that in the O3 model we perform a coherent memory access during the semihosting operation. Change-Id: Ib87fdeb70ee7a930659563230a80cce0e1372c32 Signed-off-by: Giacomo Travaglini Reviewed-by: Andreas Sandberg Reviewed-on: https://gem5-review.googlesource.com/8370 Maintainer: Andreas Sandberg --- src/arch/arm/isa/templates/semihost.isa | 86 ++++++++++++++++++++++++++++++++ src/arch/arm/isa/templates/templates.isa | 5 +- 2 files changed, 90 insertions(+), 1 deletion(-) create mode 100644 src/arch/arm/isa/templates/semihost.isa diff --git a/src/arch/arm/isa/templates/semihost.isa b/src/arch/arm/isa/templates/semihost.isa new file mode 100644 index 000000000..c6b36bc68 --- /dev/null +++ b/src/arch/arm/isa/templates/semihost.isa @@ -0,0 +1,86 @@ +// -*- mode:c++ -*- +// Copyright (c) 2018 ARM Limited +// All rights reserved +// +// The license below extends only to copyright in the software and shall +// not be construed as granting a license to any other intellectual +// property including but not limited to intellectual property relating +// to a hardware implementation of the functionality of the software +// licensed hereunder. You may use the software subject to the license +// terms below provided that you ensure that this notice is replicated +// unmodified and in its entirety in all distributions of the software, +// modified or unmodified, in source code or in binary form. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer; +// redistributions in binary form must reproduce the above copyright +// notice, this list of conditions and the following disclaimer in the +// documentation and/or other materials provided with the distribution; +// neither the name of the copyright holders nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +// +// Authors: Giacomo Travaglini + +// +// A new class of Semihosting constructor templates has been added. +// Their main purpose is to check if the Exception Generation +// Instructions (HLT, SVC) are actually a semihosting command. +// If that is the case, the IsMemBarrier flag is raised, so that +// in the O3 model we perform a coherent memory access during +// the semihosting operation. +// Please note: since we don't have a thread context pointer in the +// constructor we cannot check if semihosting is enabled in the +// system. This is not affecting functional correctness, it just +// means O3 models will flush the LSQ even if semihosting is disabled +// when a semihosting immediate is recognized. + +def template SemihostConstructor {{ + %(class_name)s::%(class_name)s(ExtMachInst machInst, uint64_t _imm) + : %(base_class)s("%(mnemonic)s", machInst, %(op_class)s, _imm) + { + %(constructor)s; + if (!(condCode == COND_AL || condCode == COND_UC)) { + for (int x = 0; x < _numDestRegs; x++) { + _srcRegIdx[_numSrcRegs++] = _destRegIdx[x]; + } + } + + // In AArch32 semihosting commands can be issued by either + // SVC and HLT instructions. Another degree of freedom + // is added by the operating mode (Arm or Thumb) + auto semihost_imm = machInst.thumb? %(thumb_semihost)s : + %(arm_semihost)s; + if (_imm == semihost_imm) { + flags[IsMemBarrier] = true; + } + } +}}; + +def template SemihostConstructor64 {{ + %(class_name)s::%(class_name)s(ExtMachInst machInst, uint64_t _imm) + : %(base_class)s("%(mnemonic)s", machInst, %(op_class)s, _imm) + { + %(constructor)s; + + // In AArch64 there is only one instruction for issuing + // semhosting commands: HLT #0xF000 + if (_imm == 0xF000) { + flags[IsMemBarrier] = true; + } + } +}}; diff --git a/src/arch/arm/isa/templates/templates.isa b/src/arch/arm/isa/templates/templates.isa index 2263cdff4..6d525738d 100644 --- a/src/arch/arm/isa/templates/templates.isa +++ b/src/arch/arm/isa/templates/templates.isa @@ -1,6 +1,6 @@ // -*- mode:c++ -*- -// Copyright (c) 2010-2011 ARM Limited +// Copyright (c) 2010-2011,2018 ARM Limited // All rights reserved // // The license below extends only to copyright in the software and shall @@ -40,6 +40,9 @@ //Basic instruction templates ##include "basic.isa" +//Semihosting instruction templates +##include "semihost.isa" + //Templates for AArch64 bit data instructions. ##include "data64.isa" -- cgit v1.2.3