From: Yong Li <yong...@intel.com> Impelement the SpeculationBarrier with implementations consisting of fence instruction which provides finer-grain memory orderings. Data Barrier: fence rw,rw Instruction Barrier: fence.i; fence r,r More detail is in Chapter 17, RVWMO Memory Consistency Model https://github.com/riscv/riscv-isa-manual
Cc: Warkentin, Andrei <andrei.warken...@intel.com> Cc: Evan, Chai <evan.c...@intel.com> Cc: Sunil V L <suni...@ventanamicro.com> Cc: Tuan Phan <tp...@ventanamicro.com> Signed-off-by: Yong Li <yong...@intel.com> --- MdePkg/Library/BaseLib/BaseLib.inf | 1 + .../BaseLib/RiscV64/SpeculationBarrier.S | 34 +++++++++++++++++++ 2 files changed, 35 insertions(+) create mode 100755 MdePkg/Library/BaseLib/RiscV64/SpeculationBarrier.S diff --git a/MdePkg/Library/BaseLib/BaseLib.inf b/MdePkg/Library/BaseLib/BaseLib.inf index 3a48492b1a..03c7b02e82 100644 --- a/MdePkg/Library/BaseLib/BaseLib.inf +++ b/MdePkg/Library/BaseLib/BaseLib.inf @@ -404,6 +404,7 @@ RiscV64/CpuScratch.S | GCC RiscV64/ReadTimer.S | GCC RiscV64/RiscVMmu.S | GCC + RiscV64/SpeculationBarrier.S | GCC [Sources.LOONGARCH64] Math64.c diff --git a/MdePkg/Library/BaseLib/RiscV64/SpeculationBarrier.S b/MdePkg/Library/BaseLib/RiscV64/SpeculationBarrier.S new file mode 100755 index 0000000000..581a765399 --- /dev/null +++ b/MdePkg/Library/BaseLib/RiscV64/SpeculationBarrier.S @@ -0,0 +1,34 @@ +##------------------------------------------------------------------------------ +# +# SpeculationBarrier() for RISCV64 +# +# Copyright (c) 2023, Intel Corporation. All rights reserved. +# +# SPDX-License-Identifier: BSD-2-Clause-Patent +# +##------------------------------------------------------------------------------ + +.text +.p2align 2 + +ASM_GLOBAL ASM_PFX(SpeculationBarrier) + + +#/** +# Uses as a barrier to stop speculative execution. +# +# Ensures that no later instruction will execute speculatively, until all prior +# instructions have completed. +# +#**/ +#VOID +#EFIAPI +#SpeculationBarrier ( +# VOID +# ); +# +ASM_PFX(SpeculationBarrier): + fence rw,rw + fence.i + fence r,r + ret -- 2.25.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#105350): https://edk2.groups.io/g/devel/message/105350 Mute This Topic: https://groups.io/mt/99163570/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
