diff mbox series

[v7,02/16] target/riscv/tcg: do not use "!generic" CPU checks

Message ID 20231031203916.197332-3-dbarboza@ventanamicro.com
State New
Headers show
Series rv64i CPU, RVA22U64 profile support | expand

Commit Message

Daniel Henrique Barboza Oct. 31, 2023, 8:39 p.m. UTC 
Our current logic in get/setters of MISA and multi-letter extensions
works because we have only 2 CPU types, generic and vendor, and by using
"!generic" we're implying that we're talking about vendor CPUs. When adding
a third CPU type this logic will break so let's handle it beforehand.

In set_misa_ext_cfg() and set_multi_ext_cfg(), check for "vendor" cpu instead
of "not generic". The "generic CPU" checks remaining are from
riscv_cpu_add_misa_properties() and cpu_add_multi_ext_prop() before
applying default values for the extensions.

This leaves us with:

- vendor CPUs will not allow extension enablement, all other CPUs will;

- generic CPUs will inherit default values for extensions, all others
  won't.

And now we can add a new, third CPU type, that will allow extensions to
be enabled and will not inherit defaults, without changing the existing
logic.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/tcg/tcg-cpu.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

Comments

Andrew Jones Nov. 1, 2023, 9:20 a.m. UTC | #1 
On Tue, Oct 31, 2023 at 05:39:02PM -0300, Daniel Henrique Barboza wrote:
> Our current logic in get/setters of MISA and multi-letter extensions
> works because we have only 2 CPU types, generic and vendor, and by using
> "!generic" we're implying that we're talking about vendor CPUs. When adding
> a third CPU type this logic will break so let's handle it beforehand.
> 
> In set_misa_ext_cfg() and set_multi_ext_cfg(), check for "vendor" cpu instead
> of "not generic". The "generic CPU" checks remaining are from
> riscv_cpu_add_misa_properties() and cpu_add_multi_ext_prop() before
> applying default values for the extensions.
> 
> This leaves us with:
> 
> - vendor CPUs will not allow extension enablement, all other CPUs will;
> 
> - generic CPUs will inherit default values for extensions, all others
>   won't.
> 
> And now we can add a new, third CPU type, that will allow extensions to
> be enabled and will not inherit defaults, without changing the existing
> logic.
> 
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>  target/riscv/tcg/tcg-cpu.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
diff mbox series

Patch

diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c
index 093bda2e75..f54069d06f 100644
--- a/target/riscv/tcg/tcg-cpu.c
+++ b/target/riscv/tcg/tcg-cpu.c
@@ -612,6 +612,11 @@  static bool riscv_cpu_is_generic(Object *cpu_obj)
     return object_dynamic_cast(cpu_obj, TYPE_RISCV_DYNAMIC_CPU) != NULL;
 }
 
+static bool riscv_cpu_is_vendor(Object *cpu_obj)
+{
+    return object_dynamic_cast(cpu_obj, TYPE_RISCV_VENDOR_CPU) != NULL;
+}
+
 /*
  * We'll get here via the following path:
  *
@@ -674,7 +679,7 @@  static void cpu_set_misa_ext_cfg(Object *obj, Visitor *v, const char *name,
     target_ulong misa_bit = misa_ext_cfg->misa_bit;
     RISCVCPU *cpu = RISCV_CPU(obj);
     CPURISCVState *env = &cpu->env;
-    bool generic_cpu = riscv_cpu_is_generic(obj);
+    bool vendor_cpu = riscv_cpu_is_vendor(obj);
     bool prev_val, value;
 
     if (!visit_type_bool(v, name, &value, errp)) {
@@ -688,7 +693,7 @@  static void cpu_set_misa_ext_cfg(Object *obj, Visitor *v, const char *name,
     }
 
     if (value) {
-        if (!generic_cpu) {
+        if (vendor_cpu) {
             g_autofree char *cpuname = riscv_cpu_get_name(cpu);
             error_setg(errp, "'%s' CPU does not allow enabling extensions",
                        cpuname);
@@ -793,7 +798,7 @@  static void cpu_set_multi_ext_cfg(Object *obj, Visitor *v, const char *name,
 {
     const RISCVCPUMultiExtConfig *multi_ext_cfg = opaque;
     RISCVCPU *cpu = RISCV_CPU(obj);
-    bool generic_cpu = riscv_cpu_is_generic(obj);
+    bool vendor_cpu = riscv_cpu_is_vendor(obj);
     bool prev_val, value;
 
     if (!visit_type_bool(v, name, &value, errp)) {
@@ -817,7 +822,7 @@  static void cpu_set_multi_ext_cfg(Object *obj, Visitor *v, const char *name,
         return;
     }
 
-    if (value && !generic_cpu) {
+    if (value && vendor_cpu) {
         g_autofree char *cpuname = riscv_cpu_get_name(cpu);
         error_setg(errp, "'%s' CPU does not allow enabling extensions",
                    cpuname);