From a5b6055cb93d0b5e337db5490c44756af9eacf7b Mon Sep 17 00:00:00 2001
From: Robert Schilling <rschilling@rivosinc.com>
Date: Sat, 14 Dec 2024 19:16:53 +0100
Subject: [PATCH] [topgen] Deepcopy parameter when mangeling

Otherwise, the same parameter of a difference instance
would be overwritten

Signed-off-by: Robert Schilling <rschilling@rivosinc.com>
---
 util/reggen/params.py      |  2 ++
 util/topgen/intermodule.py | 18 +++++++++++++++---
 util/topgen/merge.py       |  8 ++++++++
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/util/reggen/params.py b/util/reggen/params.py
index a790370fc0566..bd006224296d4 100644
--- a/util/reggen/params.py
+++ b/util/reggen/params.py
@@ -96,12 +96,14 @@ def __init__(self,
         self.default = default
         self.local = local
         self.expose = expose
+        self.name_top = None
 
     def as_dict(self) -> Dict[str, object]:
         rd = super().as_dict()
         rd['default'] = self.default
         rd['local'] = 'true' if self.local else 'false'
         rd['expose'] = 'true' if self.expose else 'false'
+        rd['name_top'] = self.name_top
         return rd
 
 
diff --git a/util/topgen/intermodule.py b/util/topgen/intermodule.py
index 6bcc339e163f1..6ea2211ad1602 100644
--- a/util/topgen/intermodule.py
+++ b/util/topgen/intermodule.py
@@ -778,8 +778,20 @@ def check_intermodule(topcfg: Dict, prefix: str) -> int:
             err, rsp_struct = check_intermodule_field(rsp_struct)
             error += err
 
-            total_width += rsp_struct["width"]
-            widths.append(rsp_struct["width"])
+            if isinstance(rsp_struct["width"], Parameter):
+                param = rsp_struct["width"]
+                if param.expose:
+                    # If it's a top-level exposed parameter, we need to find definition from there
+                    module = lib.get_module_by_name(topcfg, req_m)
+                    width = int(module['param_decl'].get(param.name, param.default))
+                else:
+                    width = int(rsp_struct["width"].default)
+            else:
+                width = rsp_struct["width"]
+                assert isinstance(rsp_struct["width"], int)
+
+            total_width += width
+            widths.append(width)
 
             # Type check
             # If no package was declared, it is declared with an empty string
@@ -828,7 +840,7 @@ def check_intermodule(topcfg: Dict, prefix: str) -> int:
             if param.expose:
                 # If it's a top-level exposed parameter, we need to find definition from there
                 module = lib.get_module_by_name(topcfg, req_m)
-                width = int(module['param_decl'].get(param.name, req_struct["width"].default))
+                width = int(module['param_decl'].get(param.name, param.default))
             else:
                 width = int(req_struct["width"].default)
         else:
diff --git a/util/topgen/merge.py b/util/topgen/merge.py
index ca8d087a17713..6ddabcc20b900 100644
--- a/util/topgen/merge.py
+++ b/util/topgen/merge.py
@@ -173,6 +173,14 @@ def elaborate_instance(instance, block: IpBlock):
         if isinstance(s['width'], Parameter):
             for p in instance["param_list"]:
                 if p['name'] == s['width'].name:
+                    # When mangling the name, we first need to deep copy the param. Parameters in
+                    # signals have a reference to a parameter. If we have multiple instances of the
+                    # same IP, then their signals would reference the same single parameter. If we
+                    # would mangle that directly, we all signals of all IPs would reference to that
+                    # single mangled paramter. Since parameters are instance dependent, that would
+                    # fail. Therefore, copy the parameter first to have a unique paramter for that
+                    # particular signal and instance, which is safe to mangle.
+                    s['width'] = deepcopy(s['width'])
                     s['width'].name_top = p['name_top']
 
     # An instance must either have a 'base_addr' address or a 'base_addrs'