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Re: [PATCH 1/2] target/riscv: Add Zacas ISA extension support
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From: |
Weiwei Li |
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Subject: |
Re: [PATCH 1/2] target/riscv: Add Zacas ISA extension support |
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Date: |
Fri, 2 Jun 2023 23:04:30 +0800 |
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User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 |
On 2023/6/2 20:16, Rob Bradford wrote:
This commit adds support for the the amocas.{w,d,q} instructions behind
a new property to enable that instruction.
Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
---
I also implemented an initial version for this extension without any
tests a few days ago.
You can find it in https://github.com/plctlab/plct-qemu/tree/plct-zacas-dev.
Hope it can help you.
target/riscv/cpu.c | 4 +
target/riscv/cpu.h | 1 +
target/riscv/insn32.decode | 5 +
target/riscv/insn_trans/trans_rvzacas.c.inc | 146 ++++++++++++++++++++
target/riscv/translate.c | 1 +
5 files changed, 157 insertions(+)
create mode 100644 target/riscv/insn_trans/trans_rvzacas.c.inc
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index db0875fb43..e99833eb4a 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -82,6 +82,7 @@ static const struct isa_ext_data isa_edata_arr[] = {
ISA_EXT_DATA_ENTRY(zicsr, PRIV_VERSION_1_10_0, ext_icsr),
ISA_EXT_DATA_ENTRY(zifencei, PRIV_VERSION_1_10_0, ext_ifencei),
ISA_EXT_DATA_ENTRY(zihintpause, PRIV_VERSION_1_10_0, ext_zihintpause),
+ ISA_EXT_DATA_ENTRY(zacas, PRIV_VERSION_1_12_0, ext_zacas),
ISA_EXT_DATA_ENTRY(zawrs, PRIV_VERSION_1_12_0, ext_zawrs),
ISA_EXT_DATA_ENTRY(zfh, PRIV_VERSION_1_11_0, ext_zfh),
ISA_EXT_DATA_ENTRY(zfhmin, PRIV_VERSION_1_11_0, ext_zfhmin),
@@ -1604,6 +1605,9 @@ static Property riscv_cpu_extensions[] = {
DEFINE_PROP_BOOL("x-zvfh", RISCVCPU, cfg.ext_zvfh, false),
DEFINE_PROP_BOOL("x-zvfhmin", RISCVCPU, cfg.ext_zvfhmin, false),
+ /* Atomic CAS (Zacas) */
+ DEFINE_PROP_BOOL("x-zacas", RISCVCPU, cfg.ext_zacas, false),
+
DEFINE_PROP_END_OF_LIST(),
};
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index de7e43126a..ac4d9e8e9c 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -436,6 +436,7 @@ struct RISCVCPUConfig {
bool ext_smaia;
bool ext_ssaia;
bool ext_sscofpmf;
+ bool ext_zacas;
bool rvv_ta_all_1s;
bool rvv_ma_all_1s;
diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index 73d5d1b045..97d17ee520 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -255,6 +255,11 @@ amomax_d 10100 . . ..... ..... 011 ..... 0101111 @atom_st
amominu_d 11000 . . ..... ..... 011 ..... 0101111 @atom_st
amomaxu_d 11100 . . ..... ..... 011 ..... 0101111 @atom_st
+# *** Zacas Extension
+amocas_w 00101 . . ..... ..... 010 ..... 0101111 @atom_st
+amocas_d 00101 . . ..... ..... 011 ..... 0101111 @atom_st
+amocas_q 00101 . . ..... ..... 100 ..... 0101111 @atom_st
+
# *** RV32F Standard Extension ***
flw ............ ..... 010 ..... 0000111 @i
fsw ....... ..... ..... 010 ..... 0100111 @s
diff --git a/target/riscv/insn_trans/trans_rvzacas.c.inc
b/target/riscv/insn_trans/trans_rvzacas.c.inc
new file mode 100644
index 0000000000..3f1b58ee8a
--- /dev/null
+++ b/target/riscv/insn_trans/trans_rvzacas.c.inc
@@ -0,0 +1,146 @@
+/*
+ * RISC-V translation routines for Zacas extension
+ *
+ * Copyright (c) 2023 Rivos Inc
+ *
+ * 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_ZACAS(ctx) do { \
+ if (!ctx->cfg_ptr->ext_zacas) { \
+ return false; \
+ } \
+} while (0)
+
+static bool amocas_tl(DisasContext *ctx, arg_atomic *a, MemOp mop)
+{
+ TCGv retv = dest_gpr(ctx, a->rd);
+ TCGv addr = get_address(ctx, a->rs1, 0);
+ TCGv newv = get_gpr(ctx, a->rs2, EXT_ZERO);
+ TCGv cmpv = get_gpr(ctx, a->rd, EXT_ZERO);
+
+ decode_save_opc(ctx);
+ tcg_gen_atomic_cmpxchg_tl(retv, addr, cmpv, newv, ctx->mem_idx, mop);
+ gen_set_gpr(ctx, a->rd, retv);
+
+ return true;
+}
+
+#if TARGET_LONG_BITS == 32
+static bool trans_amocas_w(DisasContext *ctx, arg_amocas_w *a)
+{
+ REQUIRE_ZACAS(ctx);
+ return amocas_tl(ctx, a, MO_TESL | MO_ALIGN);
+}
+#else
+static bool trans_amocas_w(DisasContext *ctx, arg_amocas_w *a)
+{
+ REQUIRE_64BIT(ctx);
+ REQUIRE_ZACAS(ctx);
+ ctx->ol = MXL_RV32;
+ return amocas_tl(ctx, a, MO_TESL | MO_ALIGN);
+}
+#endif
This seems unnecessary to use different trans function for RV32 and RV64.
tcg_gen_atomic_cmpxchg_tl itself will do the actually cmp and xchg
operation based on size in memop
instead of the target long size.
+
+#if TARGET_LONG_BITS == 32
We commonly use TARGET_RISCV32 instead of TARGET_LONG_BITS in similar
cases.
+static bool trans_amocas_d(DisasContext *ctx, arg_amocas_w *a)
+{
+ TCGv_i64 retv, newv, cmpv;
+ TCGv_i32 cmpv_l, cmpv_h, newv_l, newv_h;
+ TCGv addr;
+
+ REQUIRE_ZACAS(ctx);
+
+ if (a->rd % 2 == 1 || a->rs2 % 2 == 1) {
+ return false;
+ }
+
+ addr = get_address(ctx, a->rs1, 0);
+ cmpv_l = get_gpr(ctx, a->rd, 0);
It's better to use EXT_NONE instead of 0 in this and following cases.
+ cmpv_h = a->rd == 0 ? get_gpr(ctx, 0, 0) : get_gpr(ctx, a->rd + 1, 0);
We can use ctx->zero for get_gpr(ctx, 0, 0) directly here.
+ cmpv = tcg_temp_new_i64();
+ tcg_gen_concat_i32_i64(cmpv, cmpv_l, cmpv_h);
+ newv_l = get_gpr(ctx, a->rs2, 0);
+ newv_h = a->rs2 == 0 ? get_gpr(ctx, 0, 0) : get_gpr(ctx, a->rs2 + 1, 0);
+ newv = tcg_temp_new_i64();
+ tcg_gen_concat_i32_i64(newv, newv_l, newv_h);
+ retv = tcg_temp_new_i64();
+
+ decode_save_opc(ctx);
+ tcg_gen_atomic_cmpxchg_i64(retv, addr, cmpv, newv, ctx->mem_idx,
+ MO_TESQ | MO_ALIGN);
+
+ if (a->rd != 0) {
+ TCGv_i32 retv_l = tcg_temp_new_i32();
+ TCGv_i32 retv_h = tcg_temp_new_i32();
+ tcg_gen_extr_i64_i32(retv_l, retv_h, retv);
+ gen_set_gpr(ctx, a->rd, retv_l);
+ gen_set_gpr(ctx, a->rd + 1, retv_h);
+ }
+
+ return true;
+}
+#else
+static bool trans_amocas_d(DisasContext *ctx, arg_amocas_w *a)
+{
+ REQUIRE_64BIT(ctx);
This seems not correct. amocas_d can work on RV32, so I think it can
also work on RV64 with xl = 32
+ REQUIRE_ZACAS(ctx);
+ return amocas_tl(ctx, a, MO_TESQ | MO_ALIGN);
+}
+#endif
+
+#if TARGET_LONG_BITS == 32
+static bool trans_amocas_q(DisasContext *ctx, arg_amocas_w *a)
+{
+ return false;
+}
This case is unnecessary.
We can just add REQUIRE_64BIT(ctx) in following trans_amocas_q
+#else
+static bool trans_amocas_q(DisasContext *ctx, arg_amocas_w *a)
+{
+ TCGv_i128 retv, newv, cmpv;
+ TCGv_i64 cmpv_l, cmpv_h, newv_l, newv_h;
+ TCGv addr;
+
+ REQUIRE_64BIT(ctx);
+ REQUIRE_ZACAS(ctx);
+
+ if (a->rd % 2 == 1 || a->rs2 % 2 == 1) {
+ return false;
+ }
+
+ addr = get_address(ctx, a->rs1, 0);
+ cmpv_l = get_gpr(ctx, a->rd, 0);
+ cmpv_h = a->rd == 0 ? get_gpr(ctx, 0, 0) : get_gpr(ctx, a->rd + 1, 0);
+ cmpv = tcg_temp_new_i128();
+ tcg_gen_concat_i64_i128(cmpv, cmpv_l, cmpv_h);
+ newv_l = get_gpr(ctx, a->rs2, 0);
+ newv_h = a->rs2 == 0 ? get_gpr(ctx, 0, 0) : get_gpr(ctx, a->rs2 + 1, 0);
+ newv = tcg_temp_new_i128();
+ tcg_gen_concat_i64_i128(newv, newv_l, newv_h);
+ retv = tcg_temp_new_i128();
+
+ decode_save_opc(ctx);
+ tcg_gen_atomic_cmpxchg_i128(retv, addr, cmpv, newv, ctx->mem_idx,
+ MO_TEUO | MO_ALIGN);
+
+ if (a->rd != 0) {
+ TCGv_i64 retv_l = tcg_temp_new_i64();
+ TCGv_i64 retv_h = tcg_temp_new_i64();
+ tcg_gen_extr_i128_i64(retv_l, retv_h, retv);
+ gen_set_gpr(ctx, a->rd, retv_l);
+ gen_set_gpr(ctx, a->rd + 1, retv_h);
+ }
+
+ return true;
+}
+#endif
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 928da0d3f0..55438f5ebf 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -1074,6 +1074,7 @@ static uint32_t opcode_at(DisasContextBase *dcbase,
target_ulong pc)
#include "insn_trans/trans_rvv.c.inc"
#include "insn_trans/trans_rvb.c.inc"
#include "insn_trans/trans_rvzicond.c.inc"
+#include "insn_trans/trans_rvzacas.c.inc"
#include "insn_trans/trans_rvzawrs.c.inc"
#include "insn_trans/trans_rvzicbo.c.inc"
#include "insn_trans/trans_rvzfh.c.inc"