Am Donnerstag, 2. Juni 2022, 15:40:17 CEST schrieb Christoph Muellner: > From: Christoph Muellner <christoph.muell...@vrull.eu> > > This patch adds support for the Zawrs ISA extension. > Given the current (incomplete) implementation of reservation sets > there seems to be no way to provide a full emulation of the WRS > instruction (wake on reservation set invalidation or timeout or > interrupt). Therefore, we just pretend that an interrupt occured, > exit the execution loop and finally continue execution. > > The specification can be found here: > https://github.com/riscv/riscv-zawrs/blob/main/zawrs.adoc > > Note, that the Zawrs extension is not frozen or ratified yet. > Therefore this patch is an RFC and not intended to get merged. > > Changes since v1: > * Adding zawrs to the ISA string that is passed to the kernel > > Signed-off-by: Christoph Muellner <christoph.muell...@vrull.eu>
together with the Linux-kernel patch Tested-by: Heiko Stuebner <he...@sntech.de> > --- > target/riscv/cpu.c | 2 + > target/riscv/cpu.h | 1 + > target/riscv/insn32.decode | 3 ++ > target/riscv/insn_trans/trans_rvzawrs.c.inc | 48 +++++++++++++++++++++ > target/riscv/translate.c | 1 + > 5 files changed, 55 insertions(+) > create mode 100644 target/riscv/insn_trans/trans_rvzawrs.c.inc > > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c > index a91253d4bd..95858f04bd 100644 > --- a/target/riscv/cpu.c > +++ b/target/riscv/cpu.c > @@ -877,6 +877,7 @@ static Property riscv_cpu_properties[] = { > DEFINE_PROP_BOOL("svnapot", RISCVCPU, cfg.ext_svnapot, false), > DEFINE_PROP_BOOL("svpbmt", RISCVCPU, cfg.ext_svpbmt, false), > > + DEFINE_PROP_BOOL("zawrs", RISCVCPU, cfg.ext_zawrs, true), > DEFINE_PROP_BOOL("zba", RISCVCPU, cfg.ext_zba, true), > DEFINE_PROP_BOOL("zbb", RISCVCPU, cfg.ext_zbb, true), > DEFINE_PROP_BOOL("zbc", RISCVCPU, cfg.ext_zbc, true), > @@ -1031,6 +1032,7 @@ static void riscv_isa_string_ext(RISCVCPU *cpu, char > **isa_str, int max_str_len) > struct isa_ext_data isa_edata_arr[] = { > ISA_EDATA_ENTRY(zicsr, ext_icsr), > ISA_EDATA_ENTRY(zifencei, ext_ifencei), > + ISA_EDATA_ENTRY(zawrs, ext_zawrs), > ISA_EDATA_ENTRY(zfh, ext_zfh), > ISA_EDATA_ENTRY(zfhmin, ext_zfhmin), > ISA_EDATA_ENTRY(zfinx, ext_zfinx), > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h > index f08c3e8813..2ef2efe22e 100644 > --- a/target/riscv/cpu.h > +++ b/target/riscv/cpu.h > @@ -380,6 +380,7 @@ struct RISCVCPUConfig { > bool ext_h; > bool ext_j; > bool ext_v; > + bool ext_zawrs; > bool ext_zba; > bool ext_zbb; > bool ext_zbc; > diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode > index 4033565393..ce20eab738 100644 > --- a/target/riscv/insn32.decode > +++ b/target/riscv/insn32.decode > @@ -111,6 +111,9 @@ wfi 0001000 00101 00000 000 00000 1110011 > sfence_vma 0001001 ..... ..... 000 00000 1110011 @sfence_vma > sfence_vm 0001000 00100 ..... 000 00000 1110011 @sfence_vm > > +# *** Zawrs Instruction Extension *** > +wrs 000000010000 ..... 000 00000 1110011 @sfence_vm > + > # *** RV32I Base Instruction Set *** > lui .................... ..... 0110111 @u > auipc .................... ..... 0010111 @u > diff --git a/target/riscv/insn_trans/trans_rvzawrs.c.inc > b/target/riscv/insn_trans/trans_rvzawrs.c.inc > new file mode 100644 > index 0000000000..38b71d0085 > --- /dev/null > +++ b/target/riscv/insn_trans/trans_rvzawrs.c.inc > @@ -0,0 +1,48 @@ > +/* > + * RISC-V translation routines for the RISC-V Zawrs Extension. > + * > + * Copyright (c) 2022 Christoph Muellner, christoph.muell...@vrull.io > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2 or later, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License along > with > + * this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#define REQUIRE_ZAWRS(ctx) do { \ > + if (!ctx->cfg_ptr->ext_zawrs) { \ > + return false; \ > + } \ > +} while (0) > + > +static bool trans_wrs(DisasContext *ctx, arg_sfence_vm *a) > +{ > + REQUIRE_ZAWRS(ctx); > + > + /* > + * We may continue if one or more of the following conditions are met: > + * a) reservation set is invalid > + * b) rs1 != 0 and X(rs1) < time CSR > + * c) interrupt observed > + * > + * A reservation set can be invalidated by any store to a reserved > + * memory location. However, that's currently not implemented in QEMU. > + * So let's just exit the CPU loop and pretend that an interrupt occured. > + */ > + > + /* Clear the load reservation (if any). */ > + tcg_gen_movi_tl(load_res, -1); > + > + gen_set_pc_imm(ctx, ctx->pc_succ_insn); > + tcg_gen_exit_tb(NULL, 0); > + ctx->base.is_jmp = DISAS_NORETURN; > + > + return true; > +} > diff --git a/target/riscv/translate.c b/target/riscv/translate.c > index 55a4713af2..3f0140d124 100644 > --- a/target/riscv/translate.c > +++ b/target/riscv/translate.c > @@ -1005,6 +1005,7 @@ static uint32_t opcode_at(DisasContextBase *dcbase, > target_ulong pc) > #include "insn_trans/trans_rvh.c.inc" > #include "insn_trans/trans_rvv.c.inc" > #include "insn_trans/trans_rvb.c.inc" > +#include "insn_trans/trans_rvzawrs.c.inc" > #include "insn_trans/trans_rvzfh.c.inc" > #include "insn_trans/trans_rvk.c.inc" > #include "insn_trans/trans_privileged.c.inc" >