[PULL,63/63] target/riscv: configure and turn on vector extension from command line

Commit Message

Alistair Francis June 26, 2020, 9:44 p.m. UTC

From: LIU Zhiwei <[e-mail]>

Vector extension is default off. The only way to use vector extension is
1. use cpu rv32 or rv64
2. turn on it by command line
   "-cpu rv64,x-v=true,vlen=128,elen=64,vext_spec=v0.7.1".

vlen is the vector register length, default value is 128 bit.
elen is the max operator size in bits, default value is 64 bit.
vext_spec is the vector specification version, default value is v0.7.1.
These properties can be specified with other values.

Signed-off-by: LIU Zhiwei <[e-mail]>
Reviewed-by: Alistair Francis <[e-mail]>
Reviewed-by: Richard Henderson <[e-mail]>
Message-id: [e-mail]
Signed-off-by: Alistair Francis <[e-mail]>
---
 target/riscv/cpu.h |  4 +++-
 target/riscv/cpu.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 1 deletion(-)

Patch

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 0ad51c6580..eef20ca6e5 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -92,7 +92,7 @@  typedef struct CPURISCVState CPURISCVState;
 
 #include "pmp.h"
 
-#define RV_VLEN_MAX 512
+#define RV_VLEN_MAX 256
 
 FIELD(VTYPE, VLMUL, 0, 2)
 FIELD(VTYPE, VSEW, 2, 3)
@@ -279,12 +279,14 @@  typedef struct RISCVCPU {
         bool ext_s;
         bool ext_u;
         bool ext_h;
+        bool ext_v;
         bool ext_counters;
         bool ext_ifencei;
         bool ext_icsr;
 
         char *priv_spec;
         char *user_spec;
+        char *vext_spec;
         uint16_t vlen;
         uint16_t elen;
         bool mmu;
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index d525cfb687..228b9bdb5d 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -430,6 +430,45 @@  static void riscv_cpu_realize(DeviceState *dev, Error **errp)
         if (cpu->cfg.ext_h) {
             target_misa |= RVH;
         }
+        if (cpu->cfg.ext_v) {
+            target_misa |= RVV;
+            if (!is_power_of_2(cpu->cfg.vlen)) {
+                error_setg(errp,
+                        "Vector extension VLEN must be power of 2");
+                return;
+            }
+            if (cpu->cfg.vlen > RV_VLEN_MAX || cpu->cfg.vlen < 128) {
+                error_setg(errp,
+                        "Vector extension implementation only supports VLEN "
+                        "in the range [128, %d]", RV_VLEN_MAX);
+                return;
+            }
+            if (!is_power_of_2(cpu->cfg.elen)) {
+                error_setg(errp,
+                        "Vector extension ELEN must be power of 2");
+                return;
+            }
+            if (cpu->cfg.elen > 64 || cpu->cfg.vlen < 8) {
+                error_setg(errp,
+                        "Vector extension implementation only supports ELEN "
+                        "in the range [8, 64]");
+                return;
+            }
+            if (cpu->cfg.vext_spec) {
+                if (!g_strcmp0(cpu->cfg.vext_spec, "v0.7.1")) {
+                    vext_version = VEXT_VERSION_0_07_1;
+                } else {
+                    error_setg(errp,
+                           "Unsupported vector spec version '%s'",
+                           cpu->cfg.vext_spec);
+                    return;
+                }
+            } else {
+                qemu_log("vector verison is not specified, "
+                        "use the default value v0.7.1\n");
+            }
+            set_vext_version(env, vext_version);
+        }
 
         set_misa(env, RVXLEN | target_misa);
     }
@@ -469,10 +508,14 @@  static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("u", RISCVCPU, cfg.ext_u, true),
     /* This is experimental so mark with 'x-' */
     DEFINE_PROP_BOOL("x-h", RISCVCPU, cfg.ext_h, false),
+    DEFINE_PROP_BOOL("x-v", RISCVCPU, cfg.ext_v, false),
     DEFINE_PROP_BOOL("Counters", RISCVCPU, cfg.ext_counters, true),
     DEFINE_PROP_BOOL("Zifencei", RISCVCPU, cfg.ext_ifencei, true),
     DEFINE_PROP_BOOL("Zicsr", RISCVCPU, cfg.ext_icsr, true),
     DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec),
+    DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec),
+    DEFINE_PROP_UINT16("vlen", RISCVCPU, cfg.vlen, 128),
+    DEFINE_PROP_UINT16("elen", RISCVCPU, cfg.elen, 64),
     DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true),
     DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true),
     DEFINE_PROP_END_OF_LIST(),