3 files changed, 44 insertions, 1 deletions
diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
index d611a60470..a744010332 100644
--- a/target/loongarch/cpu.c
+++ b/target/loongarch/cpu.c
@@ -19,7 +19,7 @@
 #include "cpu.h"
 #include "internals.h"
 #include "fpu/softfloat-helpers.h"
-#include "cpu-csr.h"
+#include "csr.h"
 #ifndef CONFIG_USER_ONLY
 #include "system/reset.h"
 #endif
@@ -375,6 +375,33 @@ static int loongarch_cpu_mmu_index(CPUState *cs, bool ifetch)
     return MMU_DA_IDX;
 }
 
+static void loongarch_la464_init_csr(Object *obj)
+{
+#ifndef CONFIG_USER_ONLY
+    static bool initialized;
+    LoongArchCPU *cpu = LOONGARCH_CPU(obj);
+    CPULoongArchState *env = &cpu->env;
+    int i, num;
+
+    if (!initialized) {
+        initialized = true;
+        num = FIELD_EX64(env->CSR_PRCFG1, CSR_PRCFG1, SAVE_NUM);
+        for (i = num; i < 16; i++) {
+            set_csr_flag(LOONGARCH_CSR_SAVE(i), CSRFL_UNUSED);
+        }
+        set_csr_flag(LOONGARCH_CSR_IMPCTL1, CSRFL_UNUSED);
+        set_csr_flag(LOONGARCH_CSR_IMPCTL2, CSRFL_UNUSED);
+        set_csr_flag(LOONGARCH_CSR_MERRCTL, CSRFL_UNUSED);
+        set_csr_flag(LOONGARCH_CSR_MERRINFO1, CSRFL_UNUSED);
+        set_csr_flag(LOONGARCH_CSR_MERRINFO2, CSRFL_UNUSED);
+        set_csr_flag(LOONGARCH_CSR_MERRENTRY, CSRFL_UNUSED);
+        set_csr_flag(LOONGARCH_CSR_MERRERA, CSRFL_UNUSED);
+        set_csr_flag(LOONGARCH_CSR_MERRSAVE, CSRFL_UNUSED);
+        set_csr_flag(LOONGARCH_CSR_CTAG, CSRFL_UNUSED);
+    }
+#endif
+}
+
 static void loongarch_la464_initfn(Object *obj)
 {
     LoongArchCPU *cpu = LOONGARCH_CPU(obj);
@@ -470,6 +497,7 @@ static void loongarch_la464_initfn(Object *obj)
     env->CSR_PRCFG3 = FIELD_DP64(env->CSR_PRCFG3, CSR_PRCFG3, STLB_WAYS, 7);
     env->CSR_PRCFG3 = FIELD_DP64(env->CSR_PRCFG3, CSR_PRCFG3, STLB_SETS, 8);
 
+    loongarch_la464_init_csr(obj);
     loongarch_cpu_post_init(obj);
 }
 
diff --git a/target/loongarch/csr.c b/target/loongarch/csr.c
index 62c1815bfb..87bd24e8cd 100644
--- a/target/loongarch/csr.c
+++ b/target/loongarch/csr.c
@@ -112,3 +112,16 @@ CSRInfo *get_csr(unsigned int csr_num)
 
     return csr;
 }
+
+bool set_csr_flag(unsigned int csr_num, int flag)
+{
+    CSRInfo *csr;
+
+    csr = get_csr(csr_num);
+    if (!csr) {
+        return false;
+    }
+
+    csr->flags |= flag;
+    return true;
+}
diff --git a/target/loongarch/csr.h b/target/loongarch/csr.h
index caad832545..deb1aacc33 100644
--- a/target/loongarch/csr.h
+++ b/target/loongarch/csr.h
@@ -13,6 +13,7 @@ enum {
     CSRFL_READONLY = (1 << 0),
     CSRFL_EXITTB   = (1 << 1),
     CSRFL_IO       = (1 << 2),
+    CSRFL_UNUSED   = (1 << 3),
 };
 
 typedef struct {
@@ -23,4 +24,5 @@ typedef struct {
 } CSRInfo;
 
 CSRInfo *get_csr(unsigned int csr_num);
+bool set_csr_flag(unsigned int csr_num, int flag);
 #endif /* TARGET_LOONGARCH_CSR_H */