Re: [PATCH 02/22] target/riscv: introduce RISCVCPUDef

[Richard Henderson]

On 2/6/25 10:26, Paolo Bonzini wrote:

Start putting all the CPU definitions in a struct.  Later this will replace
instance_init functions with declarative code, for now just remove the
ugly cast of class_data.

...

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index ed9da692030..29cfae38b75 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -2955,7 +2955,7 @@ static void riscv_cpu_class_init(ObjectClass *c, void 
*data)
  {
      RISCVCPUClass *mcc = RISCV_CPU_CLASS(c);

- mcc->misa_mxl_max = (uint32_t)(uintptr_t)data;

+    mcc->misa_mxl_max = ((RISCVCPUDef *)data)->misa_mxl_max;
      riscv_cpu_validate_misa_mxl(mcc);
  }

@@ -3051,40 +3051,48 @@ void riscv_isa_write_fdt(RISCVCPU *cpu, void *fdt, char *nodename)

  }
  #endif

-#define DEFINE_DYNAMIC_CPU(type_name, misa_mxl_max, initfn) \

+#define DEFINE_DYNAMIC_CPU(type_name, misa_mxl_max_, initfn) \
      {                                                       \
          .name = (type_name),                                \
          .parent = TYPE_RISCV_DYNAMIC_CPU,                   \
          .instance_init = (initfn),                          \
          .class_init = riscv_cpu_class_init,                 \
-        .class_data = (void *)(misa_mxl_max)                \
+        .class_data = &((RISCVCPUDef) {                     \
+             .misa_mxl_max = (misa_mxl_max_),               \
+        }),                                                 \

Drop the unnecessary ().

It would be nice if this were const, i.e.

  .class_data = (void *) &(const RISCVCPUDef){
      ...
  },

This will in fact create an anonymous object in .rodata.

We have other uses that do the extra casting away const,
e.g. armsse_variants in hw/arm/armsse.c.  Although I suspect
*all* usage of .class_init can and should be with const data.
An unrelated cleanup, to be sure.


r~