[alert,dv] Make the base driver explicit that it's just for alerts

hw/dv/sv/alert_esc_agent/alert_esc_base_driver.sv → hw/dv/sv/alert_esc_agent/alert_base_driver.sv

@@ -1,41 +1,43 @@
 // Copyright lowRISC contributors (OpenTitan project).
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
-//
 
-// ---------------------------------------------
-// Alert_esc_base driver
-// ---------------------------------------------
-class alert_esc_base_driver extends dv_base_driver#(alert_esc_seq_item, alert_esc_agent_cfg);
-  alert_esc_seq_item r_alert_ping_send_q[$], r_alert_rsp_q[$], r_esc_rsp_q[$],
+// Virtual base class used for alert_sender_driver and alert_receiver_driver
+
+virtual class alert_base_driver extends dv_base_driver#(alert_esc_seq_item, alert_esc_agent_cfg);
+  alert_esc_seq_item r_alert_ping_send_q[$], r_alert_rsp_q[$],
                      s_alert_send_q[$], s_alert_ping_rsp_q[$];
 
-  `uvm_component_utils(alert_esc_base_driver)
+  `uvm_component_utils(alert_base_driver)
 
   extern function new (string name, uvm_component parent);
-  // drive trans received from sequencer
+
+  // Take items from the sequencer and drive them. This implements a task from dv_base_driver.
   extern virtual task get_and_drive();
-  extern virtual task drive_req();
-  extern virtual task get_req();
 
-endclass : alert_esc_base_driver
+  // Monitor seq_item_port and add the items to the various queues
+  //
+  // This is run by get_and_drive.
+  extern local task get_req();
+
+  // Drive items that have been added to the various queues by get_req
+  //
+  // This should run forever and is started by get_and_drive.
+  pure virtual task drive_req();
+endclass
 
-function alert_esc_base_driver::new (string name, uvm_component parent);
+function alert_base_driver::new (string name, uvm_component parent);
   super.new(name, parent);
 endfunction : new
 
-task alert_esc_base_driver::get_and_drive();
+task alert_base_driver::get_and_drive();
   fork
     get_req();
     drive_req();
-  join_none
-endtask : get_and_drive
+  join
+endtask
 
-task alert_esc_base_driver::drive_req();
-  `uvm_fatal(`gfn, "this is implemented as pure virtual task - please extend")
-endtask : drive_req
-
-task alert_esc_base_driver::get_req();
+task alert_base_driver::get_req();
   @(posedge cfg.vif.rst_n);
   forever begin
     alert_esc_seq_item req_clone;
@@ -45,12 +47,16 @@ task alert_esc_base_driver::get_req();
     // receiver mode
     if (req.r_alert_ping_send) r_alert_ping_send_q.push_back(req_clone);
     if (req.r_alert_rsp)       r_alert_rsp_q.push_back(req_clone);
-    if (req.r_esc_rsp)         r_esc_rsp_q.push_back(req_clone);
     // sender mode
     if (req.s_alert_send)      s_alert_send_q.push_back(req_clone);
     if (req.s_alert_ping_rsp)  s_alert_ping_rsp_q.push_back(req_clone);
+
+    if (req.r_esc_rsp) begin
+      `uvm_error(get_full_name(), "Alert driver cannot drive an esc item")
+    end
+
     `uvm_info(`gfn, $sformatf({"Driver received item (after pushing): req.r_alert_ping_send=%0d",
-                               " | req.r_alert_rsp=%0d | req.r_esc_rsp=%0d"},
-                              req.r_alert_ping_send, req.r_alert_rsp, req.r_esc_rsp), UVM_DEBUG)
+                               " | req.r_alert_rsp=%0d"},
+                              req.r_alert_ping_send, req.r_alert_rsp), UVM_DEBUG)
   end
 endtask : get_req

hw/dv/sv/alert_esc_agent/alert_esc_agent.core

@@ -11,13 +11,13 @@ filesets:
       - lowrisc:prim:all:0.1
       - lowrisc:dv:dv_lib
     files:
+      - alert_base_driver.sv: {is_include_file: true}
       - alert_esc_if.sv
       - alert_esc_probe_if.sv
       - alert_esc_agent_pkg.sv
       - alert_esc_agent_cfg.sv: {is_include_file: true}
       - alert_esc_agent.sv: {is_include_file: true}
       - alert_esc_agent_cov.sv: {is_include_file: true}
-      - alert_esc_base_driver.sv: {is_include_file: true}
       - alert_sender_driver.sv: {is_include_file: true}
       - alert_receiver_driver.sv: {is_include_file: true}
       - alert_sender_driver.sv: {is_include_file: true}

hw/dv/sv/alert_esc_agent/alert_esc_agent.sv

@@ -7,7 +7,7 @@
 // ---------------------------------------------
 class alert_esc_agent extends dv_base_agent#(
     .CFG_T           (alert_esc_agent_cfg),
-    .DRIVER_T        (alert_esc_base_driver),
+    .DRIVER_T        (dv_base_driver#(alert_esc_seq_item, alert_esc_agent_cfg)),
     .SEQUENCER_T     (alert_esc_sequencer),
     .MONITOR_T       (alert_esc_base_monitor),
     .COV_T           (alert_esc_agent_cov)

hw/dv/sv/alert_esc_agent/alert_esc_agent_pkg.sv

@@ -59,7 +59,7 @@ package alert_esc_agent_pkg;
   `include "alert_esc_seq_item.sv"
   `include "alert_esc_agent_cfg.sv"
   `include "alert_esc_agent_cov.sv"
-  `include "alert_esc_base_driver.sv"
+  `include "alert_base_driver.sv"
   `include "alert_sender_driver.sv"
   `include "alert_receiver_driver.sv"
   `include "esc_sender_driver.sv"

hw/dv/sv/alert_esc_agent/alert_receiver_driver.sv

@@ -4,7 +4,7 @@
 
 // A driver that receives alerts. This is used in alert_esc_agent when configured in "device mode"
 // (so the dut is a device and the agent is expecting to receive alerts and send occasional pings)
-class alert_receiver_driver extends alert_esc_base_driver;
+class alert_receiver_driver extends alert_base_driver;
   `uvm_component_utils(alert_receiver_driver)
 
   bit working_on_alert;

hw/dv/sv/alert_esc_agent/alert_sender_driver.sv

@@ -6,7 +6,7 @@
 // ---------------------------------------------
 // Alert_handler sender driver
 // ---------------------------------------------
-class alert_sender_driver extends alert_esc_base_driver;
+class alert_sender_driver extends alert_base_driver;
 
   `uvm_component_utils(alert_sender_driver)
 

hw/dv/sv/alert_esc_agent/esc_receiver_driver.sv

@@ -2,13 +2,11 @@
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
 
-// ---------------------------------------------
-// Alert_handler receiver driver
-// ---------------------------------------------
-class esc_receiver_driver extends alert_esc_base_driver;
+// Escalation receiver driver
 
-  `uvm_component_utils(esc_receiver_driver)
+class esc_receiver_driver extends dv_base_driver#(alert_esc_seq_item, alert_esc_agent_cfg);
 
+  `uvm_component_utils(esc_receiver_driver)
 
   // Set by esc_ping_detector if it sees a single-cycle pulse on esc_p/esc_n. If set, the receiver
   // will drive a 1010 pattern on resp_p/resp_n for a while in drive_esc_resp (stopping if it
@@ -22,10 +20,11 @@ class esc_receiver_driver extends alert_esc_base_driver;
   // Overridden from dv_base_driver.
   extern virtual task reset_signals();
 
-  // Run rsp_escalator and esc_ping_detector. Does not terminate.
+  // This task runs forever. It works by running rsp_escalator (which consumes and drives items from
+  // seq_item_port) and esc_ping_detector (which responds to ping requests).
   //
-  // Overridden from alert_esc_base_driver.
-  extern virtual task drive_req();
+  // Overridden from dv_base_driver.
+  extern virtual task get_and_drive();
 
   // Run forever, detect single-cycle escalation requests. These are ping requests. When one
   // happens, set is_ping, which tells drive_esc_resp to send the 1010... pattern.
@@ -76,12 +75,12 @@ task esc_receiver_driver::reset_signals();
   end
 endtask : reset_signals
 
-task esc_receiver_driver::drive_req();
+task esc_receiver_driver::get_and_drive();
   fork
     rsp_escalator();
     esc_ping_detector();
   join
-endtask : drive_req
+endtask : get_and_drive
 
 task esc_receiver_driver::esc_ping_detector();
   forever begin
@@ -115,11 +114,12 @@ endtask : esc_ping_detector
 
 task esc_receiver_driver::rsp_escalator();
   forever begin
-    alert_esc_seq_item req, rsp;
-    wait(r_esc_rsp_q.size() > 0 && !under_reset);
-    req = r_esc_rsp_q.pop_front();
+    alert_esc_seq_item rsp;
+
+    seq_item_port.get(req);
     `downcast(rsp, req.clone());
     rsp.set_id_info(req);
+
     `uvm_info(`gfn, $sformatf("starting to send receiver item, esc_rsp=%0b int_fail=%0b",
                               req.r_esc_rsp, req.int_err), UVM_HIGH)
     fork

hw/dv/sv/alert_esc_agent/esc_sender_driver.sv

@@ -1,52 +1,40 @@
 // Copyright lowRISC contributors (OpenTitan project).
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
-//
 
-// ---------------------------------------------
-// Esc sender driver
-// ---------------------------------------------
-class esc_sender_driver extends alert_esc_base_driver;
+// Escalation sender driver
 
+class esc_sender_driver extends dv_base_driver#(alert_esc_seq_item, alert_esc_agent_cfg);
   `uvm_component_utils(esc_sender_driver)
 
-
   extern function new (string name, uvm_component parent);
   extern virtual task reset_signals();
   extern virtual task get_and_drive();
-  extern virtual task drive_esc();
-  extern virtual task do_reset();
 
+  extern local task do_reset();
 endclass : esc_sender_driver
 
 function esc_sender_driver::new (string name, uvm_component parent);
   super.new(name, parent);
 endfunction : new
 
 task esc_sender_driver::reset_signals();
-  do_reset();
   forever begin
-    @(negedge cfg.vif.rst_n);
     under_reset = 1;
     do_reset();
     @(posedge cfg.vif.rst_n);
     under_reset = 0;
+
+    @(negedge cfg.vif.rst_n);
   end
 endtask : reset_signals
 
 task esc_sender_driver::get_and_drive();
   // LC_CTRL uses virtual interface to directly drive escalation requests.
   // Other escalation handshakes are checked in prim_esc direct sequence.
   // So the following task is not implemented.
-  drive_esc();
-endtask : get_and_drive
-
-task esc_sender_driver::drive_esc();
-  // LC_CTRL uses virtual interface to directly drive escalation requests.
-  // Other escalation handshakes are checked in prim_esc direct sequence.
-  // So this task is not implemented.
   wait(!under_reset);
-endtask : drive_esc
+endtask : get_and_drive
 
 task esc_sender_driver::do_reset();
   cfg.vif.esc_tx_int.esc_p <= 1'b0;