[dv,csr] Support non-HRO REGWEN fields

REGWEN fields may exist in CSRs that are non-HRO, but
those registers must not be modified indirectly by
CSR testing.

Signed-off-by: Adrian Lees <[email protected]>

util/reggen/fpv_csr.sv.tpl

@@ -139,8 +139,29 @@ module ${mod_base}_csr_assert_fpv import tlul_pkg::*;
   // Assign regwen to registers. If the register does not have regwen, it will default to value 1.
   logic [${num_hro_regs}:0] regwen;
   % for hro_reg in hro_regs_list:
-<% regwen = hro_reg.regwen %>\
+<%
+     regwen = hro_reg.regwen
+     hidden_regwen = True
+     mubi_regwen = False
+     mubi_width = 4
+     # Locate the REGWEN register and determine its type.
+     for reg in hro_regs_list:
+       if reg.name == regwen:
+         hidden_regwen = False
+         if reg.fields[0].mubi:
+           mubi_regwen = True
+           mubi_width = reg.fields[0].bits.width()
+         endif
+       endif
+     endfor
+%>\
     % if regwen == None:
+  assign regwen[${hro_map.get(hro_reg.offset)[0]}] = 1;
+    % elif mubi_regwen:
+  assign regwen[${hro_map.get(hro_reg.offset)[0]}] =
+                  prim_mubi_pkg::mubi${mubi_width}_test_true_strict(prim_mubi_pkg::mubi${mubi_width}_t'(`REGWEN_PATH.${regwen.lower()}_qs));
+    % elif hidden_regwen:
+  // Register is controlled by a REGWEN that is not 'hwo' and not supported in fpv_csr
   assign regwen[${hro_map.get(hro_reg.offset)[0]}] = 1;
     % else:
   assign regwen[${hro_map.get(hro_reg.offset)[0]}] = `REGWEN_PATH.${regwen.lower()}_qs;