target/loongarch: Add dynamic function access with CSR register

With CSR register, dynamic function access is used for CSR register
access in TCG mode, so that csr info can be used by other modules.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>

Author: bibo-mao

target/loongarch/tcg/insn_trans/trans_privileged.c.inc

@@ -76,7 +76,7 @@ enum {
 #define CSR_OFF(NAME) \
     CSR_OFF_FLAGS(NAME, 0)
 
-static const CSRInfo csr_info[] = {
+static CSRInfo csr_info[] = {
     CSR_OFF_FLAGS(CRMD, CSRFL_EXITTB),
     CSR_OFF(PRMD),
     CSR_OFF_FLAGS(EUEN, CSRFL_EXITTB),
@@ -160,9 +160,9 @@ static bool check_plv(DisasContext *ctx)
     return false;
 }
 
-static const CSRInfo *get_csr(unsigned csr_num)
+static CSRInfo *get_csr(unsigned csr_num)
 {
-    const CSRInfo *csr;
+    CSRInfo *csr;
 
     if (csr_num >= ARRAY_SIZE(csr_info)) {
         return NULL;
@@ -174,6 +174,37 @@ static const CSRInfo *get_csr(unsigned csr_num)
     return csr;
 }
 
+static bool set_csr_trans_func(unsigned int csr_num, GenCSRRead readfn,
+                               GenCSRWrite writefn)
+{
+    CSRInfo *csr;
+
+    csr = get_csr(csr_num);
+    if (!csr) {
+        return false;
+    }
+
+    csr->readfn = readfn;
+    csr->writefn = writefn;
+    return true;
+}
+
+#define SET_CSR_FUNC(NAME, read, write)                 \
+        set_csr_trans_func(LOONGARCH_CSR_##NAME, read, write)
+
+void loongarch_csr_translate_init(void)
+{
+    SET_CSR_FUNC(ESTAT, NULL, gen_helper_csrwr_estat);
+    SET_CSR_FUNC(ASID,  NULL, gen_helper_csrwr_asid);
+    SET_CSR_FUNC(PGD,   gen_helper_csrrd_pgd, NULL);
+    SET_CSR_FUNC(PWCL,  NULL, gen_helper_csrwr_pwcl);
+    SET_CSR_FUNC(CPUID, gen_helper_csrrd_cpuid, NULL);
+    SET_CSR_FUNC(TCFG,  NULL, gen_helper_csrwr_tcfg);
+    SET_CSR_FUNC(TVAL,  gen_helper_csrrd_tval, NULL);
+    SET_CSR_FUNC(TICLR, NULL, gen_helper_csrwr_ticlr);
+}
+#undef SET_CSR_FUNC
+
 static bool check_csr_flags(DisasContext *ctx, const CSRInfo *csr, bool write)
 {
     if ((csr->flags & CSRFL_READONLY) && write) {

target/loongarch/tcg/tcg_loongarch.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * QEMU LoongArch TCG interface
+ *
+ * Copyright (c) 2025 Loongson Technology Corporation Limited
+ */
+#ifndef TARGET_LOONGARCH_TCG_LOONGARCH_H
+#define TARGET_LOONGARCH_TCG_LOONGARCH_H
+
+void loongarch_csr_translate_init(void);
+
+#endif  /* TARGET_LOONGARCH_TCG_LOONGARCH_H */

target/loongarch/tcg/translate.c

@@ -16,6 +16,7 @@
 #include "exec/log.h"
 #include "qemu/qemu-print.h"
 #include "fpu/softfloat.h"
+#include "tcg_loongarch.h"
 #include "translate.h"
 #include "internals.h"
 #include "vec.h"
@@ -358,4 +359,8 @@ void loongarch_translate_init(void)
                     offsetof(CPULoongArchState, lladdr), "lladdr");
     cpu_llval = tcg_global_mem_new(tcg_env,
                     offsetof(CPULoongArchState, llval), "llval");
+
+#ifndef CONFIG_USER_ONLY
+    loongarch_csr_translate_init();
+#endif
 }