[dv,core_ibex] Add push_pull agent for Scramble IF

This allows us to actually use Icache in our tests beecause
before this commit key_valid was tied to 0 which means everytime
we receive a FENCE.I instruction, we wouldn't be able to successfully
flag inval_done. Which means we weren't probably using ICache correctly.

Signed-off-by: Canberk Topal <ctopal@lowrisc.org>

dv/uvm/core_ibex/env/core_ibex_env.sv

@@ -15,6 +15,7 @@ class core_ibex_env extends uvm_env;
 `endif
   core_ibex_vseqr                vseqr;
   core_ibex_env_cfg              cfg;
+  scrambling_key_agent           scrambling_key_agent_h;
 
   `uvm_component_utils(core_ibex_env)
   `uvm_component_new
@@ -38,6 +39,12 @@ class core_ibex_env extends uvm_env;
       cosim_agent = null;
     end
 `endif
+
+    scrambling_key_agent_h = scrambling_key_agent::type_id::create("scrambling_key_agent_h", this);
+    uvm_config_db#(scrambling_key_agent_cfg)::set(this, "scrambling_key_agent_h", "cfg",
+                                                  cfg.scrambling_key_cfg);
+    cfg.scrambling_key_cfg.agent_type = push_pull_agent_pkg::PullAgent;
+    cfg.scrambling_key_cfg.if_mode = dv_utils_pkg::Device;
     // Create virtual sequencer
     vseqr = core_ibex_vseqr::type_id::create("vseqr", this);
   endfunction : build_phase

dv/uvm/core_ibex/env/core_ibex_env_cfg.sv

@@ -4,16 +4,17 @@
 
 class core_ibex_env_cfg extends uvm_object;
 
-  bit       enable_irq_single_seq;
-  bit       enable_irq_multiple_seq;
-  bit       enable_irq_nmi_seq;
-  bit       enable_nested_irq;
-  bit       enable_debug_seq;
-  bit       disable_cosim;
-  bit[31:0] max_interval;
-  bit       require_signature_addr;
-  string    signature_addr_str;
-  bit[31:0] signature_addr;
+  bit                           enable_irq_single_seq;
+  bit                           enable_irq_multiple_seq;
+  bit                           enable_irq_nmi_seq;
+  bit                           enable_nested_irq;
+  bit                           enable_debug_seq;
+  bit                           disable_cosim;
+  bit[31:0]                     max_interval;
+  bit                           require_signature_addr;
+  string                        signature_addr_str;
+  bit[31:0]                     signature_addr;
+  rand scrambling_key_agent_cfg scrambling_key_cfg;
 
   `uvm_object_utils_begin(core_ibex_env_cfg)
     `uvm_field_int(enable_irq_single_seq,   UVM_DEFAULT)
@@ -25,6 +26,7 @@ class core_ibex_env_cfg extends uvm_object;
     `uvm_field_int(max_interval, UVM_DEFAULT)
     `uvm_field_int(require_signature_addr, UVM_DEFAULT)
     `uvm_field_int(signature_addr, UVM_DEFAULT)
+    `uvm_field_object(scrambling_key_cfg, UVM_DEFAULT)
   `uvm_object_utils_end
 
   function new(string name = "");
@@ -39,6 +41,7 @@ class core_ibex_env_cfg extends uvm_object;
     void'($value$plusargs("require_signature_addr=%0d", require_signature_addr));
     void'($value$plusargs("signature_addr=%s", signature_addr_str));
     signature_addr = signature_addr_str.atohex();
+    scrambling_key_cfg = scrambling_key_agent_cfg::type_id::create("scrambling_key_cfg");
   endfunction
 
 endclass

dv/uvm/core_ibex/env/core_ibex_env_pkg.sv

@@ -12,6 +12,14 @@ package core_ibex_env_pkg;
   import ibex_mem_intf_agent_pkg::*;
   import irq_agent_pkg::*;
   import ibex_cosim_agent_pkg::*;
+  import push_pull_agent_pkg::*;
+
+  typedef push_pull_agent#(
+    .DeviceDataWidth(ibex_pkg::SCRAMBLE_NONCE_W + ibex_pkg::SCRAMBLE_KEY_W)
+    ) scrambling_key_agent;
+  typedef push_pull_agent_cfg#(
+    .DeviceDataWidth(ibex_pkg::SCRAMBLE_NONCE_W + ibex_pkg::SCRAMBLE_KEY_W)
+    ) scrambling_key_agent_cfg;
 
   `include "core_ibex_vseqr.sv"
   `include "core_ibex_env_cfg.sv"

dv/uvm/core_ibex/ibex_dv.f

@@ -12,6 +12,7 @@
 +define+BOOT_ADDR=8000_0000
 +define+TRACE_EXECUTION
 +define+RVFI
++define+UVM
 
 // Shared lowRISC code
 +incdir+${LOWRISC_IP_DIR}/ip/prim/rtl
@@ -33,6 +34,7 @@ ${LOWRISC_IP_DIR}/ip/prim/rtl/prim_secded_39_32_dec.sv
 ${LOWRISC_IP_DIR}/ip/prim/rtl/prim_secded_72_64_enc.sv
 ${LOWRISC_IP_DIR}/ip/prim/rtl/prim_secded_72_64_dec.sv
 ${LOWRISC_IP_DIR}/ip/prim/rtl/prim_onehot_check.sv
+${LOWRISC_IP_DIR}/ip/prim/rtl/prim_mubi_pkg.sv
 
 // Until this list is generated by FuseSoC, we have to use manually generated
 // wrappers around the prim_* modules to instantiate the prim_generic_* ones,
@@ -99,15 +101,20 @@ ${PRJ_DIR}/rtl/ibex_top_tracing.sv
 
 // Core DV files
 ${PRJ_DIR}/vendor/google_riscv-dv/src/riscv_signature_pkg.sv
++incdir+${LOWRISC_IP_DIR}/dv/sv/dv_utils
++incdir+${LOWRISC_IP_DIR}/dv/sv/dv_base_reg
++incdir+${LOWRISC_IP_DIR}/dv/sv/csr_utils
++incdir+${LOWRISC_IP_DIR}/dv/sv/dv_lib
++incdir+${LOWRISC_IP_DIR}/dv/sv/mem_model
++incdir+${LOWRISC_IP_DIR}/dv/sv/push_pull_agent
++incdir+${LOWRISC_IP_DIR}/dv/sv/push_pull_agent/seq_lib
++incdir+${LOWRISC_IP_DIR}/dv/sv/str_utils
 +incdir+${PRJ_DIR}/dv/uvm/core_ibex/env
 +incdir+${PRJ_DIR}/dv/uvm/core_ibex/fcov
 +incdir+${PRJ_DIR}/dv/uvm/core_ibex/tests
 +incdir+${PRJ_DIR}/dv/uvm/core_ibex/common/ibex_mem_intf_agent
 +incdir+${PRJ_DIR}/dv/uvm/core_ibex/common/irq_agent
 +incdir+${PRJ_DIR}/dv/uvm/core_ibex/common/ibex_cosim_agent
-+incdir+${LOWRISC_IP_DIR}/dv/sv/mem_model
-+incdir+${LOWRISC_IP_DIR}/dv/sv/dv_utils
-+incdir+${LOWRISC_IP_DIR}/dv/sv/str_utils
 +incdir+${PRJ_DIR}/dv/cosim
 ${PRJ_DIR}/dv/uvm/bus_params_pkg/bus_params_pkg.sv
 ${LOWRISC_IP_DIR}/dv/sv/common_ifs/clk_rst_if.sv
@@ -115,7 +122,12 @@ ${LOWRISC_IP_DIR}/dv/sv/common_ifs/pins_if.sv
 ${LOWRISC_IP_DIR}/dv/sv/str_utils/str_utils_pkg.sv
 ${LOWRISC_IP_DIR}/dv/sv/dv_utils/dv_test_status_pkg.sv
 ${LOWRISC_IP_DIR}/dv/sv/dv_utils/dv_utils_pkg.sv
+${LOWRISC_IP_DIR}/dv/sv/dv_base_reg/dv_base_reg_pkg.sv
+${LOWRISC_IP_DIR}/dv/sv/csr_utils/csr_utils_pkg.sv
+${LOWRISC_IP_DIR}/dv/sv/dv_lib/dv_lib_pkg.sv
 ${LOWRISC_IP_DIR}/dv/sv/mem_model/mem_model_pkg.sv
+${LOWRISC_IP_DIR}/dv/sv/push_pull_agent/push_pull_if.sv
+${LOWRISC_IP_DIR}/dv/sv/push_pull_agent/push_pull_agent_pkg.sv
 ${PRJ_DIR}/dv/uvm/core_ibex/common/ibex_mem_intf_agent/ibex_mem_intf.sv
 ${PRJ_DIR}/dv/uvm/core_ibex/common/ibex_mem_intf_agent/ibex_mem_intf_agent_pkg.sv
 ${PRJ_DIR}/dv/uvm/core_ibex/common/irq_agent/irq_if.sv

dv/uvm/core_ibex/tb/core_ibex_tb_top.sv

@@ -10,7 +10,6 @@ module core_ibex_tb_top;
   import core_ibex_test_pkg::*;
 
   wire clk;
-  wire scramble_req;
   wire rst_n;
 
   clk_rst_if     ibex_clk_if(.clk(clk), .rst_n(rst_n));
@@ -69,6 +68,20 @@ module core_ibex_tb_top;
   parameter bit ICacheScramble            = 1'b0;
   parameter bit DbgTriggerEn              = 1'b0;
 
+  // Scrambling interface instantiation
+  logic [ibex_pkg::SCRAMBLE_KEY_W-1:0]   scramble_key;
+  logic [ibex_pkg::SCRAMBLE_NONCE_W-1:0] scramble_nonce;
+
+  // Initiate push pull interface for connection between Ibex and a scrambling key provider.
+  push_pull_if #(
+    .DeviceDataWidth(ibex_pkg::SCRAMBLE_NONCE_W + ibex_pkg::SCRAMBLE_KEY_W)
+  ) scrambling_key_if (
+    .clk(clk),
+    .rst_n(rst_n)
+  );
+
+  // key and nonce are driven by push_pull Device interface
+  assign {scramble_key, scramble_nonce} = scrambling_key_if.d_data;
 
   ibex_top_tracing #(
     .DmHaltAddr       (32'h`BOOT_ADDR + 'h0 ),
@@ -128,10 +141,10 @@ module core_ibex_tb_top;
     .irq_fast_i             (irq_vif.irq_fast           ),
     .irq_nm_i               (irq_vif.irq_nm             ),
 
-    .scramble_key_valid_i   ('0                         ),
-    .scramble_key_i         ('0                         ),
-    .scramble_nonce_i       ('0                         ),
-    .scramble_req_o         (                           ),
+    .scramble_key_valid_i   (scrambling_key_if.ack      ),
+    .scramble_key_i         (scramble_key               ),
+    .scramble_nonce_i       (scramble_nonce             ),
+    .scramble_req_o         (scrambling_key_if.req      ),
 
     .debug_req_i            (dut_if.debug_req           ),
     .crash_dump_o           (                           ),
@@ -267,6 +280,8 @@ module core_ibex_tb_top;
     uvm_config_db#(virtual irq_if)::set(null, "*", "vif", irq_vif);
     uvm_config_db#(virtual core_ibex_ifetch_if)::set(null, "*", "ifetch_if", ifetch_if);
     uvm_config_db#(virtual core_ibex_ifetch_pmp_if)::set(null, "*", "ifetch_pmp_if", ifetch_pmp_if);
+    uvm_config_db#(scrambling_key_vif)::set(
+      null, "*.env.scrambling_key_agent*", "vif", scrambling_key_if);
 
     // Expose ISA config parameters to UVM DB
     uvm_config_db#(bit)::set(null, "*", "RV32E", RV32E);

dv/uvm/core_ibex/tests/core_ibex_test_pkg.sv

@@ -14,6 +14,7 @@ package core_ibex_test_pkg;
   import riscv_signature_pkg::*;
   import ibex_pkg::*;
   import ibex_cosim_agent_pkg::*;
+  import push_pull_agent_pkg::*;
 
   typedef struct {
     ibex_pkg::opcode_e  opcode;
@@ -38,6 +39,10 @@ package core_ibex_test_pkg;
     PickErr   // Pick which memory to inject error in.
     } error_type_e;
 
+  typedef virtual push_pull_if#(
+    .DeviceDataWidth(ibex_pkg::SCRAMBLE_NONCE_W + ibex_pkg::SCRAMBLE_KEY_W)
+    ) scrambling_key_vif;
+
   `include "core_ibex_report_server.sv"
   `include "core_ibex_seq_lib.sv"
   `include "core_ibex_new_seq_lib.sv"

dv/uvm/icache/dv/tb/tb.sv

@@ -198,7 +198,7 @@ module tb #(
   end
 
 
-  // Initiate push pull interface for the OTP<->OTBN connections
+  // Initiate push pull interface for connection between Icache and a scrambling key provider.
   push_pull_if #(
     .DeviceDataWidth(194)
   ) scrambling_key_if (