target/loongarch: Allow user enable/disable LSX/LASX features

Some users may not need LSX/LASX, this patch allows the user
enable/disable LSX/LASX features.

 e.g
 '-cpu max,lsx=on,lasx=on'   (default);
 '-cpu max,lsx=on,lasx=off'  (enabled LSX);
 '-cpu max,lsx=off,lasx=on'  (enabled LASX, LSX);
 '-cpu max,lsx=off'          (disable LSX and LASX).

Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231020084925.3457084-3-gaosong@loongson.cn>

2 files changed, 69 insertions, 0 deletions

diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
index ef6922e..a60d07a 100644
--- a/target/loongarch/cpu.c
+++ b/target/loongarch/cpu.c
@@ -443,6 +443,7 @@ static void loongarch_la464_initfn(Object *obj)
     env->cpucfg[20] = data;
 
     env->CSR_ASID = FIELD_DP64(0, CSR_ASID, ASIDBITS, 0xa);
+    loongarch_cpu_post_init(obj);
 }
 
 static void loongarch_la132_initfn(Object *obj)
@@ -622,6 +623,72 @@ static const MemoryRegionOps loongarch_qemu_ops = {
 };
 #endif
 
+static bool loongarch_get_lsx(Object *obj, Error **errp)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(obj);
+    bool ret;
+
+    if (FIELD_EX32(cpu->env.cpucfg[2], CPUCFG2, LSX)) {
+        ret = true;
+    } else {
+        ret = false;
+    }
+    return ret;
+}
+
+static void loongarch_set_lsx(Object *obj, bool value, Error **errp)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(obj);
+
+    if (value) {
+        cpu->env.cpucfg[2] = FIELD_DP32(cpu->env.cpucfg[2], CPUCFG2, LSX, 1);
+    } else {
+        cpu->env.cpucfg[2] = FIELD_DP32(cpu->env.cpucfg[2], CPUCFG2, LSX, 0);
+        cpu->env.cpucfg[2] = FIELD_DP32(cpu->env.cpucfg[2], CPUCFG2, LASX, 0);
+    }
+}
+
+static bool loongarch_get_lasx(Object *obj, Error **errp)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(obj);
+    bool ret;
+
+    if (FIELD_EX32(cpu->env.cpucfg[2], CPUCFG2, LASX)) {
+        ret = true;
+    } else {
+        ret = false;
+    }
+    return ret;
+}
+
+static void loongarch_set_lasx(Object *obj, bool value, Error **errp)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(obj);
+
+    if (value) {
+	if (!FIELD_EX32(cpu->env.cpucfg[2], CPUCFG2, LSX)) {
+            cpu->env.cpucfg[2] = FIELD_DP32(cpu->env.cpucfg[2], CPUCFG2, LSX, 1);
+	}
+        cpu->env.cpucfg[2] = FIELD_DP32(cpu->env.cpucfg[2], CPUCFG2, LASX, 1);
+    } else {
+        cpu->env.cpucfg[2] = FIELD_DP32(cpu->env.cpucfg[2], CPUCFG2, LASX, 0);
+    }
+}
+
+void loongarch_cpu_post_init(Object *obj)
+{
+    LoongArchCPU *cpu = LOONGARCH_CPU(obj);
+
+    if (FIELD_EX32(cpu->env.cpucfg[2], CPUCFG2, LSX)) {
+        object_property_add_bool(obj, "lsx", loongarch_get_lsx,
+                                 loongarch_set_lsx);
+    }
+    if (FIELD_EX32(cpu->env.cpucfg[2], CPUCFG2, LASX)) {
+        object_property_add_bool(obj, "lasx", loongarch_get_lasx,
+                                 loongarch_set_lasx);
+    }
+}
+
 static void loongarch_cpu_init(Object *obj)
 {
 #ifndef CONFIG_USER_ONLY
diff --git a/target/loongarch/cpu.h b/target/loongarch/cpu.h
index 8b54cf1..9d0f79f 100644
--- a/target/loongarch/cpu.h
+++ b/target/loongarch/cpu.h
@@ -486,4 +486,6 @@ void loongarch_cpu_list(void);
 #define LOONGARCH_CPU_TYPE_NAME(model) model LOONGARCH_CPU_TYPE_SUFFIX
 #define CPU_RESOLVING_TYPE TYPE_LOONGARCH_CPU
 
+void loongarch_cpu_post_init(Object *obj);
+
 #endif /* LOONGARCH_CPU_H */