[16/22] target/riscv: generalize custom CSR functionality

Commit Message

Paolo Bonzini Feb. 6, 2025, 6:27 p.m. UTC

Signed-off-by: Paolo Bonzini <[e-mail]>
---
 target/riscv/cpu.h    | 13 +++++++++++--
 target/riscv/cpu.c    | 23 ++++++++++++++++++++++-
 target/riscv/th_csr.c | 21 +++------------------
 3 files changed, 36 insertions(+), 21 deletions(-)

Patch

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 66ce72f7d41..00ec475fbba 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -517,6 +517,8 @@  struct ArchCPU {
     const GPtrArray *decoders;
 };
 
+typedef struct RISCVCSR RISCVCSR;
+
 typedef struct RISCVCPUDef {
     RISCVMXL misa_mxl_max;  /* max mxl for this cpu */
     RISCVCPUProfile *profile;
@@ -527,6 +529,7 @@  typedef struct RISCVCPUDef {
     int satp_mode64;
     RISCVCPUConfig cfg;
     bool bare;
+    RISCVCSR *custom_csrs;
 } RISCVCPUDef;
 
 /**
@@ -862,6 +865,12 @@  typedef struct {
     uint32_t min_priv_ver;
 } riscv_csr_operations;
 
+struct RISCVCSR {
+    int csrno;
+    bool (*insertion_test)(RISCVCPU *cpu);
+    riscv_csr_operations csr_ops;
+};
+
 /* CSR function table constants */
 enum {
     CSR_TABLE_SIZE = 0x1000
@@ -926,8 +935,8 @@  target_ulong riscv_new_csr_seed(target_ulong new_value,
 uint8_t satp_mode_max_from_map(uint32_t map);
 const char *satp_mode_str(uint8_t satp_mode, bool is_32_bit);
 
-/* Implemented in th_csr.c */
-void th_register_custom_csrs(RISCVCPU *cpu);
+/* In th_csr.c */
+extern RISCVCSR th_csr_list[];
 
 const char *priv_spec_to_str(int priv_version);
 #endif /* RISCV_CPU_H */
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 18c59633d76..6c898cef625 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -471,6 +471,19 @@  static void set_satp_mode_default_map(RISCVCPU *cpu)
 }
 #endif
 
+#ifndef CONFIG_USER_ONLY
+static void riscv_register_custom_csrs(RISCVCPU *cpu, RISCVCSR *csr_list)
+{
+    for (size_t i = 0; csr_list[i].csr_ops.name; i++) {
+        int csrno = csr_list[i].csrno;
+        riscv_csr_operations *csr_ops = &csr_list[i].csr_ops;
+        if (!csr_list[i].insertion_test || csr_list[i].insertion_test(cpu)) {
+            riscv_set_csr_ops(csrno, csr_ops);
+        }
+    }
+}
+#endif
+
 #if defined(TARGET_RISCV64)
 static void rv64_thead_c906_cpu_init(Object *obj)
 {
@@ -497,7 +510,7 @@  static void rv64_thead_c906_cpu_init(Object *obj)
     cpu->cfg.mvendorid = THEAD_VENDOR_ID;
 #ifndef CONFIG_USER_ONLY
     set_satp_mode_max_supported(cpu, VM_1_10_SV39);
-    th_register_custom_csrs(cpu);
+    riscv_register_custom_csrs(cpu, th_csr_list);
 #endif
 
     /* inherited from parent obj via riscv_cpu_init() */
@@ -1301,6 +1314,9 @@  static void riscv_cpu_init(Object *obj)
     if (riscv_cpu_mxl(env) >= MXL_RV64 && mcc->def->satp_mode64 != RISCV_PROFILE_ATTR_UNUSED) {
         set_satp_mode_max_supported(RISCV_CPU(obj), mcc->def->satp_mode64);
     }
+    if (mcc->def->custom_csrs) {
+        riscv_register_custom_csrs(cpu, mcc->def->custom_csrs);
+    }
 #endif
 }
 
@@ -2791,6 +2807,11 @@  static void riscv_cpu_class_base_init(ObjectClass *c, void *data)
         mcc->def->misa_ext |= def->misa_ext;
 
         riscv_cpu_cfg_merge(&mcc->def->cfg, &def->cfg);
+
+        if (def->custom_csrs) {
+            assert(!mcc->def->custom_csrs);
+            mcc->def->custom_csrs = def->custom_csrs;
+        }
     }
 
     if (!object_class_is_abstract(c)) {
diff --git a/target/riscv/th_csr.c b/target/riscv/th_csr.c
index 990453e080e..b648004dbc6 100644
--- a/target/riscv/th_csr.c
+++ b/target/riscv/th_csr.c
@@ -27,12 +27,6 @@ 
 #define TH_SXSTATUS_MAEE        BIT(21)
 #define TH_SXSTATUS_THEADISAEE  BIT(22)
 
-typedef struct {
-    int csrno;
-    int (*insertion_test)(RISCVCPU *cpu);
-    riscv_csr_operations csr_ops;
-} riscv_csr;
-
 static RISCVException smode(CPURISCVState *env, int csrno)
 {
     if (riscv_has_ext(env, RVS)) {
@@ -55,20 +49,11 @@  static RISCVException read_th_sxstatus(CPURISCVState *env, int csrno,
     return RISCV_EXCP_NONE;
 }
 
-static riscv_csr th_csr_list[] = {
+RISCVCSR th_csr_list[] = {
     {
         .csrno = CSR_TH_SXSTATUS,
         .insertion_test = test_thead_mvendorid,
         .csr_ops = { "th.sxstatus", smode, read_th_sxstatus }
-    }
+    },
+    { }
 };
-void th_register_custom_csrs(RISCVCPU *cpu)
-{
-    for (size_t i = 0; i < ARRAY_SIZE(th_csr_list); i++) {
-        int csrno = th_csr_list[i].csrno;
-        riscv_csr_operations *csr_ops = &th_csr_list[i].csr_ops;
-        if (!th_csr_list[i].insertion_test || th_csr_list[i].insertion_test(cpu)) {
-            riscv_set_csr_ops(csrno, csr_ops);
-        }
-    }
-}