[hw,ac_range_check,rtl] Implement range check logic

Signed-off-by: Robert Schilling <[email protected]>

hw/ip_templates/ac_range_check/rtl/ac_range_check.sv.tpl

@@ -2,10 +2,11 @@
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
 
-module ${module_instance_name} 
+module ${module_instance_name}
   import tlul_pkg::*;
-  import ${module_instance_name}_reg_pkg::*; 
+  import ${module_instance_name}_reg_pkg::*;
 #(
+  parameter logic [NumAlerts-1:0] AlertAsyncOn = {NumAlerts{1'b1}}
 ) (
   input  logic                                      clk_i,
   input  logic                                      rst_ni,
@@ -60,6 +61,7 @@ module ${module_instance_name}
     reg2hw.alert_test.recov_ctrl_update_err.qe
   };
 
+  localparam logic [NumAlerts-1:0] IsFatal = {1'b1, 1'b0};
   for (genvar i = 0; i < NumAlerts; i++) begin : gen_alert_tx
     prim_alert_sender #(
       .AsyncOn(AlertAsyncOn[i]),
@@ -76,6 +78,81 @@ module ${module_instance_name}
     );
   end
 
+  //////////////////////////////////////////////////////////////////////////////
+  // Range Check Logic
+  //////////////////////////////////////////////////////////////////////////////
+
+  logic [NumRanges-1:0] deny_mask, read_mask, write_mask, execute_mask, log_enable_mask;
+
+  for (genvar i = 0; i < NumRanges; i++) begin : gen_range_checks
+    // Extend base, limit, and mask to 32-bit
+    logic [31:0] base_ext, limit_ext;
+    logic addr_hit, tor_hit;
+
+    assign base_ext  = {reg2hw.range_base[i].q, 2'b0};
+    assign limit_ext = {reg2hw.range_limit[i].q, 2'b00};
+
+    assign tor_hit   = (ctn_tl_h2d_i.a_address >= base_ext) &
+                       (ctn_tl_h2d_i.a_address < limit_ext);
+
+    // Request hits an enabled range and comparison logic
+    assign addr_hit = prim_mubi_pkg::mubi4_test_true_strict(reg2hw.range_perm[i].enable.q) &
+                      tor_hit;
+
+    // Decode the multi-bit access fields for convinient access
+    logic read_access, write_access, execute_access;
+    assign read_access = prim_mubi_pkg::mubi4_test_true_strict(reg2hw.range_perm[i].read_access.q);
+    assign write_access =
+      prim_mubi_pkg::mubi4_test_true_strict(reg2hw.range_perm[i].write_access.q);
+    assign execute_access =
+      prim_mubi_pkg::mubi4_test_true_strict(reg2hw.range_perm[i].execute_access.q);
+
+    // Access is denied if no read_, write_, or execute access is set in the permission mask
+    assign deny_mask[i] = addr_hit & ~(read_access | write_access | execute_access);
+
+    // Determine the read, write, and execute mask. Store a hit in their index
+    assign read_mask[i]    = addr_hit & read_access;
+    assign write_mask[i]   = addr_hit & write_access;
+    assign execute_mask[i] = addr_hit & execute_access;
+  end
+
+
+  // Fiddle out bits to determine if its an execute request or not
+  assign no_exec_access, exec_access;
+  assign no_exec_access = prim_mubi_pkg::mubi4_test_false_strict(ctn_tl_h2d_i.a_user.instr_type);
+  assign exec_access    = prim_mubi_pkg::mubi4_test_true_strict(ctn_tl_h2d_i.a_user.instr_type);
+
+  // Priority comparison. If the deny mask is larger than the read, write, or execute mask, there
+  // was an address match with a higher priority for the range to be denied
+  logic read_allowed, write_allowed, execute_allowed;
+  assign read_allowed  = (ctn_tl_h2d_i.a_opcode == Get) & no_exec_access & (read_mask > deny_mask);
+  assign write_allowed = ((ctn_tl_h2d_i.a_opcode == PutFullData) |
+                          (ctn_tl_h2d_i.a_opcode == PutPartialData)) & (write_mask > deny_mask);
+  assign execute_allowed = (ctn_tl_h2d_i.a_opcode == Get) & exec_access &
+                           (execute_mask > deny_mask);
+
+  // The access fails if nothing is allowed and no overwrite is present
+  logic range_check_fail;
+  assign range_check_fail =
+    ctn_tl_h2d_i.a_valid & ~(|{read_allowed, write_allowed, execute_allowed,
+                               prim_mubi_pkg::mubi4_test_true_strict(range_check_overwrite_i)});
+
+  //////////////////////////////////////////////////////////////////////////////
+  // TLUL Loopback for failing accesses
+  //////////////////////////////////////////////////////////////////////////////
+
+  tlul_request_loopback u_req_loopback (
+    .clk_i         ( clk_i                 ),
+    .rst_ni        ( rst_ni                ),
+    .squash_req_i  ( range_check_fail      ),
+    // Incoming request
+    .tl_h2d_i      ( ctn_tl_h2d_i          ),
+    .tl_d2h_o      ( ctn_tl_d2h_o          ),
+    // Outgoing request/rsp if not squashed
+    .tl_h2d_o      ( ctn_filtered_tl_h2d_o ),
+    .tl_d2h_i      ( ctn_filtered_tl_d2h_i )
+  );
+
   //////////////////////////////////////////////////////////////////////////////
   // Assertions
   //////////////////////////////////////////////////////////////////////////////

hw/top_darjeeling/ip_autogen/ac_range_check/ac_range_check.core

@@ -0,0 +1,70 @@
+CAPI=2:
+# Copyright lowRISC contributors (OpenTitan project).
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+name: lowrisc:opentitan:top_darjeeling_ac_range_check:0.1
+description: "AC Range Check RTL"
+virtual:
+  - lowrisc:ip_interfaces:ac_range_check
+
+filesets:
+  files_rtl:
+    depend:
+      - lowrisc:ip:tlul
+      - lowrisc:prim:mubi
+      - lowrisc:prim:all
+    files:
+      - rtl/ac_range_check_reg_pkg.sv
+      - rtl/ac_range_check_reg_top.sv
+      - rtl/ac_range_check.sv
+    file_type: systemVerilogSource
+
+  files_verilator_waiver:
+    depend:
+      # common waivers
+      - lowrisc:lint:common
+      - lowrisc:lint:comportable
+    files:
+      - lint/ac_range_check.vlt
+    file_type: vlt
+
+  files_ascentlint_waiver:
+    depend:
+      # common waivers
+      - lowrisc:lint:common
+      - lowrisc:lint:comportable
+    files:
+      - lint/ac_range_check.waiver
+    file_type: waiver
+
+  files_veriblelint_waiver:
+    depend:
+      # common waivers
+      - lowrisc:lint:common
+      - lowrisc:lint:comportable
+
+parameters:
+  SYNTHESIS:
+    datatype: bool
+    paramtype: vlogdefine
+
+
+targets:
+  default: &default_target
+    filesets:
+      - tool_verilator  ? (files_verilator_waiver)
+      - tool_ascentlint ? (files_ascentlint_waiver)
+      - tool_veriblelint ? (files_veriblelint_waiver)
+      - files_rtl
+    toplevel: ac_range_check
+
+  lint:
+    <<: *default_target
+    default_tool: verilator
+    parameters:
+      - SYNTHESIS=true
+    tools:
+      verilator:
+        mode: lint-only
+        verilator_options:
+          - "-Wall"