target/riscv: Convert RVXI csr insns to decodetree

Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Peer Adelt <peer.adelt@hni.uni-paderborn.de>

target/riscv/insn32.decode

@@ -22,6 +22,7 @@
 %rd        7:5
 
 %sh10    20:10
+%csr    20:12
 
 # immediates:
 %imm_i    20:s12
@@ -43,6 +44,7 @@
 @j       ....................      ..... .......         imm=%imm_j          %rd
 
 @sh      ......  ...... .....  ... ..... ....... &shift  shamt=%sh10      %rs1 %rd
+@csr     ............   .....  ... ..... .......               %csr     %rs1 %rd
 
 # *** RV32I Base Instruction Set ***
 lui      ....................       ..... 0110111 @u
@@ -84,3 +86,9 @@ or       0000000 .....    ..... 110 ..... 0110011 @r
 and      0000000 .....    ..... 111 ..... 0110011 @r
 fence    ---- pred:4 succ:4 ----- 000 ----- 0001111
 fence_i  ---- ----   ----   ----- 001 ----- 0001111
+csrrw    ............     ..... 001 ..... 1110011 @csr
+csrrs    ............     ..... 010 ..... 1110011 @csr
+csrrc    ............     ..... 011 ..... 1110011 @csr
+csrrwi   ............     ..... 101 ..... 1110011 @csr
+csrrsi   ............     ..... 110 ..... 1110011 @csr
+csrrci   ............     ..... 111 ..... 1110011 @csr

target/riscv/insn_trans/trans_rvi.inc.c

@@ -337,3 +337,82 @@ static bool trans_fence_i(DisasContext *ctx, arg_fence_i *a)
     ctx->base.is_jmp = DISAS_NORETURN;
     return true;
 }
+
+#define RISCV_OP_CSR_PRE do {\
+    source1 = tcg_temp_new(); \
+    csr_store = tcg_temp_new(); \
+    dest = tcg_temp_new(); \
+    rs1_pass = tcg_temp_new(); \
+    gen_get_gpr(source1, a->rs1); \
+    tcg_gen_movi_tl(cpu_pc, ctx->base.pc_next); \
+    tcg_gen_movi_tl(rs1_pass, a->rs1); \
+    tcg_gen_movi_tl(csr_store, a->csr); \
+    gen_io_start();\
+} while (0)
+
+#define RISCV_OP_CSR_POST do {\
+    gen_io_end(); \
+    gen_set_gpr(a->rd, dest); \
+    tcg_gen_movi_tl(cpu_pc, ctx->pc_succ_insn); \
+    tcg_gen_exit_tb(NULL, 0); \
+    ctx->base.is_jmp = DISAS_NORETURN; \
+    tcg_temp_free(source1); \
+    tcg_temp_free(csr_store); \
+    tcg_temp_free(dest); \
+    tcg_temp_free(rs1_pass); \
+} while (0)
+
+
+static bool trans_csrrw(DisasContext *ctx, arg_csrrw *a)
+{
+    TCGv source1, csr_store, dest, rs1_pass;
+    RISCV_OP_CSR_PRE;
+    gen_helper_csrrw(dest, cpu_env, source1, csr_store);
+    RISCV_OP_CSR_POST;
+    return true;
+}
+
+static bool trans_csrrs(DisasContext *ctx, arg_csrrs *a)
+{
+    TCGv source1, csr_store, dest, rs1_pass;
+    RISCV_OP_CSR_PRE;
+    gen_helper_csrrs(dest, cpu_env, source1, csr_store, rs1_pass);
+    RISCV_OP_CSR_POST;
+    return true;
+}
+
+static bool trans_csrrc(DisasContext *ctx, arg_csrrc *a)
+{
+    TCGv source1, csr_store, dest, rs1_pass;
+    RISCV_OP_CSR_PRE;
+    gen_helper_csrrc(dest, cpu_env, source1, csr_store, rs1_pass);
+    RISCV_OP_CSR_POST;
+    return true;
+}
+
+static bool trans_csrrwi(DisasContext *ctx, arg_csrrwi *a)
+{
+    TCGv source1, csr_store, dest, rs1_pass;
+    RISCV_OP_CSR_PRE;
+    gen_helper_csrrw(dest, cpu_env, rs1_pass, csr_store);
+    RISCV_OP_CSR_POST;
+    return true;
+}
+
+static bool trans_csrrsi(DisasContext *ctx, arg_csrrsi *a)
+{
+    TCGv source1, csr_store, dest, rs1_pass;
+    RISCV_OP_CSR_PRE;
+    gen_helper_csrrs(dest, cpu_env, rs1_pass, csr_store, rs1_pass);
+    RISCV_OP_CSR_POST;
+    return true;
+}
+
+static bool trans_csrrci(DisasContext *ctx, arg_csrrci *a)
+{
+    TCGv source1, csr_store, dest, rs1_pass;
+    RISCV_OP_CSR_PRE;
+    gen_helper_csrrc(dest, cpu_env, rs1_pass, csr_store, rs1_pass);
+    RISCV_OP_CSR_POST;
+    return true;
+}

target/riscv/translate.c

@@ -1476,16 +1476,11 @@ static void gen_fp_arith(DisasContext *ctx, uint32_t opc, int rd,
 static void gen_system(DisasContext *ctx, uint32_t opc, int rd, int rs1,
                        int csr)
 {
-    TCGv source1, csr_store, dest, rs1_pass, imm_rs1;
+    TCGv source1, dest;
     source1 = tcg_temp_new();
-    csr_store = tcg_temp_new();
     dest = tcg_temp_new();
-    rs1_pass = tcg_temp_new();
-    imm_rs1 = tcg_temp_new();
     gen_get_gpr(source1, rs1);
     tcg_gen_movi_tl(cpu_pc, ctx->base.pc_next);
-    tcg_gen_movi_tl(rs1_pass, rs1);
-    tcg_gen_movi_tl(csr_store, csr); /* copy into temp reg to feed to helper */
 
 #ifndef CONFIG_USER_ONLY
     /* Extract funct7 value and check whether it matches SFENCE.VMA */
@@ -1556,45 +1551,9 @@ static void gen_system(DisasContext *ctx, uint32_t opc, int rd, int rs1,
             break;
         }
         break;
-    default:
-        tcg_gen_movi_tl(imm_rs1, rs1);
-        gen_io_start();
-        switch (opc) {
-        case OPC_RISC_CSRRW:
-            gen_helper_csrrw(dest, cpu_env, source1, csr_store);
-            break;
-        case OPC_RISC_CSRRS:
-            gen_helper_csrrs(dest, cpu_env, source1, csr_store, rs1_pass);
-            break;
-        case OPC_RISC_CSRRC:
-            gen_helper_csrrc(dest, cpu_env, source1, csr_store, rs1_pass);
-            break;
-        case OPC_RISC_CSRRWI:
-            gen_helper_csrrw(dest, cpu_env, imm_rs1, csr_store);
-            break;
-        case OPC_RISC_CSRRSI:
-            gen_helper_csrrs(dest, cpu_env, imm_rs1, csr_store, rs1_pass);
-            break;
-        case OPC_RISC_CSRRCI:
-            gen_helper_csrrc(dest, cpu_env, imm_rs1, csr_store, rs1_pass);
-            break;
-        default:
-            gen_exception_illegal(ctx);
-            return;
-        }
-        gen_io_end();
-        gen_set_gpr(rd, dest);
-        /* end tb since we may be changing priv modes, to get mmu_index right */
-        tcg_gen_movi_tl(cpu_pc, ctx->pc_succ_insn);
-        tcg_gen_exit_tb(NULL, 0); /* no chaining */
-        ctx->base.is_jmp = DISAS_NORETURN;
-        break;
     }
     tcg_temp_free(source1);
-    tcg_temp_free(csr_store);
     tcg_temp_free(dest);
-    tcg_temp_free(rs1_pass);
-    tcg_temp_free(imm_rs1);
 }
 
 static void decode_RV32_64C0(DisasContext *ctx)