diff mbox series

[v4,4/4] target/riscv: add vector configure instruction

Message ID 20200210081240.11481-5-zhiwei_liu@c-sky.com (mailing list archive)
State New, archived
Headers show
Series target-riscv: support vector extension part 1 | expand

Commit Message

LIU Zhiwei Feb. 10, 2020, 8:12 a.m. UTC
vsetvl and vsetvli are two configure instructions for vl, vtype. TB flags
should update after configure instructions. The (ill, lmul, sew ) of vtype
and the bit of (VSTART == 0 && VL == VLMAX) will be placed within tb_flags.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
---
 MAINTAINERS                             |  1 +
 target/riscv/Makefile.objs              |  2 +-
 target/riscv/cpu.h                      | 61 +++++++++++++++++++---
 target/riscv/helper.h                   |  2 +
 target/riscv/insn32.decode              |  5 ++
 target/riscv/insn_trans/trans_rvv.inc.c | 69 +++++++++++++++++++++++++
 target/riscv/translate.c                | 17 +++++-
 target/riscv/vector_helper.c            | 49 ++++++++++++++++++
 8 files changed, 195 insertions(+), 11 deletions(-)
 create mode 100644 target/riscv/insn_trans/trans_rvv.inc.c
 create mode 100644 target/riscv/vector_helper.c

Comments

Richard Henderson Feb. 11, 2020, 4:56 p.m. UTC | #1
On 2/10/20 8:12 AM, LIU Zhiwei wrote:
>  static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
> -                                        target_ulong *cs_base, uint32_t *flags)
> +                                        target_ulong *cs_base, uint32_t *pflags)
>  {
> +    uint32_t flags = 0;
> +    uint32_t vlmax;
> +    uint8_t vl_eq_vlmax;

bool.

> +
>      *pc = env->pc;
>      *cs_base = 0;
> +
> +    if (env->misa & RVV) {
> +        vlmax = vext_get_vlmax(env_archcpu(env), env->vext.vtype);
> +        vl_eq_vlmax = (env->vext.vstart == 0) && (vlmax == env->vext.vl);

You might as well move the variable declarations inside this block.

> +target_ulong HELPER(vsetvl)(CPURISCVState *env, target_ulong s1,
> +     target_ulong s2)

Indentation.

> +{
> +    int vlmax, vl;
> +    RISCVCPU *cpu = env_archcpu(env);
> +    uint16_t sew = 1 << FIELD_EX64(s2, VTYPE, SEW);
> +
> +    if (sew > cpu->cfg.elen) { /* only set vill bit. */
> +        env->vext.vtype = FIELD_DP64(0, VTYPE, VILL, 1);
> +        env->vext.vl = 0;
> +        env->vext.vstart = 0;
> +        return 0;
> +    }

You're missing checks against EDIV, VILL and the RESERVED field == 0.

> +
> +    vlmax = vext_get_vlmax(cpu, s2);
> +    if (s1 <= vlmax) {
> +        vl = s1;
> +    } else {
> +        vl = vlmax;
> +    }
> +    env->vext.vl = vl;
> +    env->vext.vtype = s2;
> +    env->vext.vstart = 0;
> +    return vl;
> +}
> 


r~
LIU Zhiwei Feb. 12, 2020, 8:09 a.m. UTC | #2
On 2020/2/12 0:56, Richard Henderson wrote:
> On 2/10/20 8:12 AM, LIU Zhiwei wrote:
>>   static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
>> -                                        target_ulong *cs_base, uint32_t *flags)
>> +                                        target_ulong *cs_base, uint32_t *pflags)
>>   {
>> +    uint32_t flags = 0;
>> +    uint32_t vlmax;
>> +    uint8_t vl_eq_vlmax;
> bool.
OK.

Is it clearer to use "bool" here? Or it's wrong to use "uint8_t "?
>
>> +
>>       *pc = env->pc;
>>       *cs_base = 0;
>> +
>> +    if (env->misa & RVV) {
>> +        vlmax = vext_get_vlmax(env_archcpu(env), env->vext.vtype);
>> +        vl_eq_vlmax = (env->vext.vstart == 0) && (vlmax == env->vext.vl);
> You might as well move the variable declarations inside this block.
OK.
>
>> +target_ulong HELPER(vsetvl)(CPURISCVState *env, target_ulong s1,
>> +     target_ulong s2)
> Indentation.
OK.
>
>> +{
>> +    int vlmax, vl;
>> +    RISCVCPU *cpu = env_archcpu(env);
>> +    uint16_t sew = 1 << FIELD_EX64(s2, VTYPE, SEW);
>> +
>> +    if (sew > cpu->cfg.elen) { /* only set vill bit. */
>> +        env->vext.vtype = FIELD_DP64(0, VTYPE, VILL, 1);
>> +        env->vext.vl = 0;
>> +        env->vext.vstart = 0;
>> +        return 0;
>> +    }
> You're missing checks against EDIV, VILL and the RESERVED field == 0.
This implementation does not support "Zvediv" . So I did not check it. 
I'm not sure if I should check(ediv==0).

I missed check  "VILL" filed.  Fix up it next patch.

I'm not quite sure if I should set VILL if  the RESERVED field != 0.

>
>> +
>> +    vlmax = vext_get_vlmax(cpu, s2);
>> +    if (s1 <= vlmax) {
>> +        vl = s1;
>> +    } else {
>> +        vl = vlmax;
>> +    }
>> +    env->vext.vl = vl;
>> +    env->vext.vtype = s2;
>> +    env->vext.vstart = 0;
>> +    return vl;
>> +}
>>
>
> r~
Richard Henderson Feb. 12, 2020, 7:28 p.m. UTC | #3
On 2/12/20 12:09 AM, LIU Zhiwei wrote:
> 
> 
> On 2020/2/12 0:56, Richard Henderson wrote:
>> On 2/10/20 8:12 AM, LIU Zhiwei wrote:
>>>   static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
>>> -                                        target_ulong *cs_base, uint32_t
>>> *flags)
>>> +                                        target_ulong *cs_base, uint32_t
>>> *pflags)
>>>   {
>>> +    uint32_t flags = 0;
>>> +    uint32_t vlmax;
>>> +    uint8_t vl_eq_vlmax;
>> bool.
> OK.
> 
> Is it clearer to use "bool" here? Or it's wrong to use "uint8_t "?

It is clearer.  Using uint8_t makes me wonder what else you were going to put
in that variable, but the answer from the code below is nothing.

>>> +    if (sew > cpu->cfg.elen) { /* only set vill bit. */
>>> +        env->vext.vtype = FIELD_DP64(0, VTYPE, VILL, 1);
>>> +        env->vext.vl = 0;
>>> +        env->vext.vstart = 0;
>>> +        return 0;
>>> +    }
>> You're missing checks against EDIV, VILL and the RESERVED field == 0.
> This implementation does not support "Zvediv" . So I did not check it. I'm not
> sure if I should check(ediv==0).
> 
> I missed check  "VILL" filed.  Fix up it next patch.
> 
> I'm not quite sure if I should set VILL if  the RESERVED field != 0.


The manual says

  # If the vtype setting is not supported by the implementation,
  # then the vill bit is set in vtype, the remaining bits in
  # vtype are set to zero, and the vl register is also set
  # to zero.

So yes, you most certainly have to check ediv == 0.

By extension, I believe the entire RESERVED field should be checked.
Otherwise, we don't get the same forward compatible behaviour for the next
vector extension beyond Zvediv.


r~
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index e72b5e5f69..015e9239b5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -266,6 +266,7 @@  M: Palmer Dabbelt <palmer@dabbelt.com>
 M: Alistair Francis <Alistair.Francis@wdc.com>
 M: Sagar Karandikar <sagark@eecs.berkeley.edu>
 M: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
+M: LIU Zhiwei <zhiwei_liu@c-sky.com>
 L: qemu-riscv@nongnu.org
 S: Supported
 F: target/riscv/
diff --git a/target/riscv/Makefile.objs b/target/riscv/Makefile.objs
index ff651f69f6..ff38df6219 100644
--- a/target/riscv/Makefile.objs
+++ b/target/riscv/Makefile.objs
@@ -1,4 +1,4 @@ 
-obj-y += translate.o op_helper.o cpu_helper.o cpu.o csr.o fpu_helper.o gdbstub.o
+obj-y += translate.o op_helper.o cpu_helper.o cpu.o csr.o fpu_helper.o vector_helper.o gdbstub.o
 obj-$(CONFIG_SOFTMMU) += pmp.o
 
 ifeq ($(CONFIG_SOFTMMU),y)
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index bf2b4b55af..f857845285 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -21,6 +21,7 @@ 
 #define RISCV_CPU_H
 
 #include "hw/core/cpu.h"
+#include "hw/registerfields.h"
 #include "exec/cpu-defs.h"
 #include "fpu/softfloat-types.h"
 
@@ -98,6 +99,10 @@  typedef struct CPURISCVState CPURISCVState;
 
 #define RV_VLEN_MAX 512
 
+FIELD(VTYPE, LMUL, 0, 2)
+FIELD(VTYPE, SEW, 2, 3)
+FIELD(VTYPE, VILL, sizeof(target_ulong) * 8 - 2, 1)
+
 struct CPURISCVState {
     target_ulong gpr[32];
     uint64_t fpr[32]; /* assume both F and D extensions */
@@ -306,16 +311,61 @@  void riscv_cpu_set_fflags(CPURISCVState *env, target_ulong);
 #define TB_FLAGS_MMU_MASK   3
 #define TB_FLAGS_MSTATUS_FS MSTATUS_FS
 
+typedef CPURISCVState CPUArchState;
+typedef RISCVCPU ArchCPU;
+#include "exec/cpu-all.h"
+
+FIELD(TB_FLAGS, VL_EQ_VLMAX, 2, 1)
+FIELD(TB_FLAGS, LMUL, 3, 2)
+FIELD(TB_FLAGS, SEW, 5, 3)
+FIELD(TB_FLAGS, VILL, 8, 1)
+
+/*
+ * A simplification for VLMAX
+ * = (1 << LMUL) * VLEN / (8 * (1 << SEW))
+ * = (VLEN << LMUL) / (8 << SEW)
+ * = (VLEN << LMUL) >> (SEW + 3)
+ * = VLEN >> (SEW + 3 - LMUL)
+ */
+static inline uint32_t vext_get_vlmax(RISCVCPU *cpu, target_ulong vtype)
+{
+    uint8_t sew, lmul;
+
+    sew = FIELD_EX64(vtype, VTYPE, SEW);
+    lmul = FIELD_EX64(vtype, VTYPE, LMUL);
+    return cpu->cfg.vlen >> (sew + 3 - lmul);
+}
+
 static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
-                                        target_ulong *cs_base, uint32_t *flags)
+                                        target_ulong *cs_base, uint32_t *pflags)
 {
+    uint32_t flags = 0;
+    uint32_t vlmax;
+    uint8_t vl_eq_vlmax;
+
     *pc = env->pc;
     *cs_base = 0;
+
+    if (env->misa & RVV) {
+        vlmax = vext_get_vlmax(env_archcpu(env), env->vext.vtype);
+        vl_eq_vlmax = (env->vext.vstart == 0) && (vlmax == env->vext.vl);
+        flags = FIELD_DP32(flags, TB_FLAGS, VILL,
+                    FIELD_EX64(env->vext.vtype, VTYPE, VILL));
+        flags = FIELD_DP32(flags, TB_FLAGS, SEW,
+                    FIELD_EX64(env->vext.vtype, VTYPE, SEW));
+        flags = FIELD_DP32(flags, TB_FLAGS, LMUL,
+                    FIELD_EX64(env->vext.vtype, VTYPE, LMUL));
+        flags = FIELD_DP32(flags, TB_FLAGS, VL_EQ_VLMAX, vl_eq_vlmax);
+    } else {
+        flags = FIELD_DP32(flags, TB_FLAGS, VILL, 1);
+    }
+
 #ifdef CONFIG_USER_ONLY
-    *flags = TB_FLAGS_MSTATUS_FS;
+    flags |= TB_FLAGS_MSTATUS_FS;
 #else
-    *flags = cpu_mmu_index(env, 0) | (env->mstatus & MSTATUS_FS);
+    flags |= cpu_mmu_index(env, 0) | (env->mstatus & MSTATUS_FS);
 #endif
+    *pflags = flags;
 }
 
 int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
@@ -356,9 +406,4 @@  void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops);
 
 void riscv_cpu_register_gdb_regs_for_features(CPUState *cs);
 
-typedef CPURISCVState CPUArchState;
-typedef RISCVCPU ArchCPU;
-
-#include "exec/cpu-all.h"
-
 #endif /* RISCV_CPU_H */
diff --git a/target/riscv/helper.h b/target/riscv/helper.h
index debb22a480..3c28c7e407 100644
--- a/target/riscv/helper.h
+++ b/target/riscv/helper.h
@@ -76,3 +76,5 @@  DEF_HELPER_2(mret, tl, env, tl)
 DEF_HELPER_1(wfi, void, env)
 DEF_HELPER_1(tlb_flush, void, env)
 #endif
+/* Vector functions */
+DEF_HELPER_3(vsetvl, tl, env, tl, tl)
diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index 77f794ed70..5dc009c3cd 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -62,6 +62,7 @@ 
 @r_rm    .......   ..... ..... ... ..... ....... %rs2 %rs1 %rm %rd
 @r2_rm   .......   ..... ..... ... ..... ....... %rs1 %rm %rd
 @r2      .......   ..... ..... ... ..... ....... %rs1 %rd
+@r2_zimm . zimm:11  ..... ... ..... ....... %rs1 %rd
 
 @sfence_vma ....... ..... .....   ... ..... ....... %rs2 %rs1
 @sfence_vm  ....... ..... .....   ... ..... ....... %rs1
@@ -203,3 +204,7 @@  fcvt_w_d   1100001  00000 ..... ... ..... 1010011 @r2_rm
 fcvt_wu_d  1100001  00001 ..... ... ..... 1010011 @r2_rm
 fcvt_d_w   1101001  00000 ..... ... ..... 1010011 @r2_rm
 fcvt_d_wu  1101001  00001 ..... ... ..... 1010011 @r2_rm
+
+# *** RV32V Extension ***
+vsetvli         0 ........... ..... 111 ..... 1010111  @r2_zimm
+vsetvl          1000000 ..... ..... 111 ..... 1010111  @r
diff --git a/target/riscv/insn_trans/trans_rvv.inc.c b/target/riscv/insn_trans/trans_rvv.inc.c
new file mode 100644
index 0000000000..da82c72bbf
--- /dev/null
+++ b/target/riscv/insn_trans/trans_rvv.inc.c
@@ -0,0 +1,69 @@ 
+/*
+ * RISC-V translation routines for the RVV Standard Extension.
+ *
+ * Copyright (c) 2020 C-SKY Limited. All rights reserved.
+ *
+ * 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/>.
+ */
+
+static bool trans_vsetvl(DisasContext *ctx, arg_vsetvl * a)
+{
+    TCGv s1, s2, dst;
+    s2 = tcg_temp_new();
+    dst = tcg_temp_new();
+
+    /* Using x0 as the rs1 register specifier, encodes an infinite AVL */
+    if (a->rs1 == 0) {
+        /* As the mask is at least one bit, RV_VLEN_MAX is >= VLMAX */
+        s1 = tcg_const_tl(RV_VLEN_MAX);
+    } else {
+        s1 = tcg_temp_new();
+        gen_get_gpr(s1, a->rs1);
+    }
+    gen_get_gpr(s2, a->rs2);
+    gen_helper_vsetvl(dst, cpu_env, s1, s2);
+    gen_set_gpr(a->rd, dst);
+    tcg_gen_movi_tl(cpu_pc, ctx->pc_succ_insn);
+    exit_tb(ctx);
+    ctx->base.is_jmp = DISAS_NORETURN;
+
+    tcg_temp_free(s1);
+    tcg_temp_free(s2);
+    tcg_temp_free(dst);
+    return true;
+}
+
+static bool trans_vsetvli(DisasContext *ctx, arg_vsetvli * a)
+{
+    TCGv s1, s2, dst;
+    s2 = tcg_const_tl(a->zimm);
+    dst = tcg_temp_new();
+
+    /* Using x0 as the rs1 register specifier, encodes an infinite AVL */
+    if (a->rs1 == 0) {
+        /* As the mask is at least one bit, RV_VLEN_MAX is >= VLMAX */
+        s1 = tcg_const_tl(RV_VLEN_MAX);
+    } else {
+        s1 = tcg_temp_new();
+        gen_get_gpr(s1, a->rs1);
+    }
+    gen_helper_vsetvl(dst, cpu_env, s1, s2);
+    gen_set_gpr(a->rd, dst);
+    gen_goto_tb(ctx, 0, ctx->pc_succ_insn);
+    ctx->base.is_jmp = DISAS_NORETURN;
+
+    tcg_temp_free(s1);
+    tcg_temp_free(s2);
+    tcg_temp_free(dst);
+    return true;
+}
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 14dc71156b..cc356aabd8 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -55,6 +55,12 @@  typedef struct DisasContext {
        to reset this known value.  */
     int frm;
     bool ext_ifencei;
+    /* vector extension */
+    bool vill;
+    uint8_t lmul;
+    uint8_t sew;
+    uint16_t vlen;
+    bool vl_eq_vlmax;
 } DisasContext;
 
 #ifdef TARGET_RISCV64
@@ -704,6 +710,7 @@  static bool gen_shift(DisasContext *ctx, arg_r *a,
 #include "insn_trans/trans_rva.inc.c"
 #include "insn_trans/trans_rvf.inc.c"
 #include "insn_trans/trans_rvd.inc.c"
+#include "insn_trans/trans_rvv.inc.c"
 #include "insn_trans/trans_privileged.inc.c"
 
 /* Include the auto-generated decoder for 16 bit insn */
@@ -735,14 +742,20 @@  static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     DisasContext *ctx = container_of(dcbase, DisasContext, base);
     CPURISCVState *env = cs->env_ptr;
     RISCVCPU *cpu = RISCV_CPU(cs);
+    uint32_t tb_flags = ctx->base.tb->flags;
 
     ctx->pc_succ_insn = ctx->base.pc_first;
-    ctx->mem_idx = ctx->base.tb->flags & TB_FLAGS_MMU_MASK;
-    ctx->mstatus_fs = ctx->base.tb->flags & TB_FLAGS_MSTATUS_FS;
+    ctx->mem_idx = tb_flags & TB_FLAGS_MMU_MASK;
+    ctx->mstatus_fs = tb_flags & TB_FLAGS_MSTATUS_FS;
     ctx->priv_ver = env->priv_ver;
     ctx->misa = env->misa;
     ctx->frm = -1;  /* unknown rounding mode */
     ctx->ext_ifencei = cpu->cfg.ext_ifencei;
+    ctx->vlen = cpu->cfg.vlen;
+    ctx->vill = FIELD_EX32(tb_flags, TB_FLAGS, VILL);
+    ctx->sew = FIELD_EX32(tb_flags, TB_FLAGS, SEW);
+    ctx->lmul = FIELD_EX32(tb_flags, TB_FLAGS, LMUL);
+    ctx->vl_eq_vlmax = FIELD_EX32(tb_flags, TB_FLAGS, VL_EQ_VLMAX);
 }
 
 static void riscv_tr_tb_start(DisasContextBase *db, CPUState *cpu)
diff --git a/target/riscv/vector_helper.c b/target/riscv/vector_helper.c
new file mode 100644
index 0000000000..e0f2415345
--- /dev/null
+++ b/target/riscv/vector_helper.c
@@ -0,0 +1,49 @@ 
+/*
+ * RISC-V Vector Extension Helpers for QEMU.
+ *
+ * Copyright (c) 2020 C-SKY Limited. All rights reserved.
+ *
+ * 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/>.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/exec-all.h"
+#include "exec/helper-proto.h"
+#include <math.h>
+
+target_ulong HELPER(vsetvl)(CPURISCVState *env, target_ulong s1,
+     target_ulong s2)
+{
+    int vlmax, vl;
+    RISCVCPU *cpu = env_archcpu(env);
+    uint16_t sew = 1 << FIELD_EX64(s2, VTYPE, SEW);
+
+    if (sew > cpu->cfg.elen) { /* only set vill bit. */
+        env->vext.vtype = FIELD_DP64(0, VTYPE, VILL, 1);
+        env->vext.vl = 0;
+        env->vext.vstart = 0;
+        return 0;
+    }
+
+    vlmax = vext_get_vlmax(cpu, s2);
+    if (s1 <= vlmax) {
+        vl = s1;
+    } else {
+        vl = vlmax;
+    }
+    env->vext.vl = vl;
+    env->vext.vtype = s2;
+    env->vext.vstart = 0;
+    return vl;
+}