[csr tb] Declare registers as a macro list

All CSR addresses supported by the TB are now delared as an X
macro list. This list is then used to autogenerate the enum
type, string print helper and an array of all addresses.

The array of addresses can now be used by the randomize generator
to turn an arbitrary integer index into an address. This removes
the restriction on only generating contiguous address ranges noted
in #443.

Add missing signal csr_restore_dtret_i

Signed-off-by: Tom Roberts <tomroberts@lowrisc.org>

dv/cs_registers/reg_driver/csr_listing.def

@@ -0,0 +1,32 @@
+// Copyright lowRISC contributors.
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+
+// List all supported registers
+
+#ifndef CSR
+#error Define CSR
+#endif
+
+CSR(PMPCfg0, 0x3A0)
+CSR(PMPCfg1, 0x3A1)
+CSR(PMPCfg2, 0x3A2)
+CSR(PMPCfg3, 0x3A3)
+CSR(PMPAddr0, 0x3B0)
+CSR(PMPAddr1, 0x3B1)
+CSR(PMPAddr2, 0x3B2)
+CSR(PMPAddr3, 0x3B3)
+CSR(PMPAddr4, 0x3B4)
+CSR(PMPAddr5, 0x3B5)
+CSR(PMPAddr6, 0x3B6)
+CSR(PMPAddr7, 0x3B7)
+CSR(PMPAddr8, 0x3B8)
+CSR(PMPAddr9, 0x3B9)
+CSR(PMPAddr10, 0x3BA)
+CSR(PMPAddr11, 0x3BB)
+CSR(PMPAddr12, 0x3BC)
+CSR(PMPAddr13, 0x3BD)
+CSR(PMPAddr14, 0x3BE)
+CSR(PMPAddr15, 0x3BF)
+
+#undef CSR

dv/cs_registers/reg_driver/register_transaction.cc

@@ -8,14 +8,18 @@
 
 void RegisterTransaction::Randomize(std::default_random_engine &gen) {
   std::uniform_int_distribution<int> addr_dist_ =
-      std::uniform_int_distribution<int>(kCSRPMPCfg0, kCSRPMPAddr15);
+      std::uniform_int_distribution<int>(
+          0, (sizeof(CSRAddresses) / sizeof(uint16_t)) - 1);
   std::uniform_int_distribution<int> wdata_dist_ =
       std::uniform_int_distribution<int>(0, 0xFFFFFFFF);
   std::uniform_int_distribution<int> operation_dist_ =
       std::uniform_int_distribution<int>(kCSRRead, kCSRClear);
-  csr_addr = addr_dist_(gen);
+  // Generate a random array index, and get the address
+  csr_addr = CSRAddresses[addr_dist_(gen)];
+  // Generate a random op type
   csr_op = static_cast<CSRegisterOperation>(operation_dist_(gen));
   if (csr_op != kCSRRead) {
+    // Generate random wdata
     csr_wdata = wdata_dist_(gen);
   }
 }
@@ -46,47 +50,12 @@ std::string RegisterTransaction::RegOpString() {
 }
 
 std::string RegisterTransaction::RegAddrString() {
+  // String representation created automatically by macro
   switch (csr_addr) {
-    case kCSRPMPCfg0:
-      return "PMP Cfg 0";
-    case kCSRPMPCfg1:
-      return "PMP Cfg 1";
-    case kCSRPMPCfg2:
-      return "PMP Cfg 2";
-    case kCSRPMPCfg3:
-      return "PMP Cfg 3";
-    case kCSRPMPAddr0:
-      return "PMP Addr 0";
-    case kCSRPMPAddr1:
-      return "PMP Addr 1";
-    case kCSRPMPAddr2:
-      return "PMP Addr 2";
-    case kCSRPMPAddr3:
-      return "PMP Addr 3";
-    case kCSRPMPAddr4:
-      return "PMP Addr 4";
-    case kCSRPMPAddr5:
-      return "PMP Addr 5";
-    case kCSRPMPAddr6:
-      return "PMP Addr 6";
-    case kCSRPMPAddr7:
-      return "PMP Addr 7";
-    case kCSRPMPAddr8:
-      return "PMP Addr 8";
-    case kCSRPMPAddr9:
-      return "PMP Addr 9";
-    case kCSRPMPAddr10:
-      return "PMP Addr 10";
-    case kCSRPMPAddr11:
-      return "PMP Addr 11";
-    case kCSRPMPAddr12:
-      return "PMP Addr 12";
-    case kCSRPMPAddr13:
-      return "PMP Addr 13";
-    case kCSRPMPAddr14:
-      return "PMP Addr 14";
-    case kCSRPMPAddr15:
-      return "PMP Addr 15";
+#define CSR(reg, addr) \
+  case kCSR##reg:      \
+    return #reg;
+#include "csr_listing.def"
     default:
       return "Undef reg: " + std::to_string(csr_addr);
   }

dv/cs_registers/reg_driver/register_transaction.h

@@ -9,6 +9,18 @@
 #include <random>
 #include <string>
 
+// Enumerate the supported register types by macro expansion
+enum CSRegisterAddr : int {
+#define CSR(reg, addr) kCSR##reg = addr,
+#include "csr_listing.def"
+};
+
+// Create an indexable array of all CSR addresses
+static const uint16_t CSRAddresses[] = {
+#define CSR(reg, addr) addr,
+#include "csr_listing.def"
+};
+
 // Enumerate the four register operation types
 enum CSRegisterOperation : int {
   kCSRRead = 0,
@@ -17,30 +29,6 @@ enum CSRegisterOperation : int {
   kCSRClear = 3
 };
 
-// Enumerate the supported register types
-enum CSRegisterAddr : int {
-  kCSRPMPCfg0 = 0x3A0,
-  kCSRPMPCfg1 = 0x3A1,
-  kCSRPMPCfg2 = 0x3A2,
-  kCSRPMPCfg3 = 0x3A3,
-  kCSRPMPAddr0 = 0x3B0,
-  kCSRPMPAddr1 = 0x3B1,
-  kCSRPMPAddr2 = 0x3B2,
-  kCSRPMPAddr3 = 0x3B3,
-  kCSRPMPAddr4 = 0x3B4,
-  kCSRPMPAddr5 = 0x3B5,
-  kCSRPMPAddr6 = 0x3B6,
-  kCSRPMPAddr7 = 0x3B7,
-  kCSRPMPAddr8 = 0x3B8,
-  kCSRPMPAddr9 = 0x3B9,
-  kCSRPMPAddr10 = 0x3BA,
-  kCSRPMPAddr11 = 0x3BB,
-  kCSRPMPAddr12 = 0x3BC,
-  kCSRPMPAddr13 = 0x3BD,
-  kCSRPMPAddr14 = 0x3BE,
-  kCSRPMPAddr15 = 0x3BF
-};
-
 struct RegisterTransaction {
  public:
   void Randomize(std::default_random_engine &gen);

dv/cs_registers/tb/tb_cs_registers.sv

@@ -70,6 +70,7 @@ module tb_cs_registers #(
   logic                 csr_save_if_i;
   logic                 csr_save_id_i;
   logic                 csr_restore_mret_i;
+  logic                 csr_restore_dret_i;
   logic                 csr_save_cause_i;
   ibex_pkg::exc_cause_e csr_mcause_i;
   logic [31:0]          csr_mtval_i;