commit 5c3c8de2f9b1ad0443852a0cf784a71fe22e950f
author Vladimir Rozic <vrozic@lowrisc.org> Wed Jun 16 10:35:20 2021 +0100
committer Philipp Wagner <mail@philipp-wagner.com> Wed Jun 16 17:44:25 2021 +0100
tree 7726000162eafd850b9cc7b001ad42b7c59f11bc
parent aaf132f5696448c0c4e64a918b7a6c5a80e4e41f

[otbn] Add dif_otbn_get_insn_cnt(). Add unit test.

Signed-off-by: Vladimir Rozic <vrozic@lowrisc.org>

sw/device/lib/dif/dif_otbn.c

diff --git a/sw/device/lib/dif/dif_otbn.c b/sw/device/lib/dif/dif_otbn.c
index 94f06be..e50d290 100644
--- a/sw/device/lib/dif/dif_otbn.c
+++ b/sw/device/lib/dif/dif_otbn.c
@@ -248,6 +248,16 @@
   return kDifOtbnOk;
 }
 
+dif_otbn_result_t dif_otbn_get_insn_cnt(const dif_otbn_t *otbn,
+                                        uint32_t *insn_cnt) {
+  if (otbn == NULL || insn_cnt == NULL) {
+    return kDifOtbnBadArg;
+  }
+
+  *insn_cnt = mmio_region_read32(otbn->base_addr, OTBN_INSN_CNT_REG_OFFSET);
+  return kDifOtbnOk;
+}
+
 dif_otbn_result_t dif_otbn_imem_write(const dif_otbn_t *otbn,
                                       uint32_t offset_bytes, const void *src,
                                       size_t len_bytes) {

sw/device/lib/dif/dif_otbn.h

diff --git a/sw/device/lib/dif/dif_otbn.h b/sw/device/lib/dif/dif_otbn.h
index 41e8f66..215213f 100644
--- a/sw/device/lib/dif/dif_otbn.h
+++ b/sw/device/lib/dif/dif_otbn.h
@@ -12,6 +12,7 @@
 
 #include <stddef.h>
 #include <stdint.h>
+
 #include "sw/device/lib/base/mmio.h"
 
 #ifdef __cplusplus
@@ -256,6 +257,21 @@
                                         dif_otbn_err_bits_t *err_bits);
 
 /**
+ * Gets the number of executed OTBN instructions.
+ *
+ * Gets the number of instructions executed so far in the current OTBN run if
+ * there is one. Otherwise, gets the number executed in total in the previous
+ * OTBN run.
+ *
+ * @param otbn OTBN instance
+ * @param[out] insn_cnt The number of instructions executed by OTBN.
+ * @return `kDifOtbnBadArg` if `otbn` or `insn_cnt` is `NULL`,
+ *         `kDifOtbnOk` otherwise.
+ */
+dif_otbn_result_t dif_otbn_get_insn_cnt(const dif_otbn_t *otbn,
+                                        uint32_t *insn_cnt);
+
+/**
  * Write an OTBN application into its instruction memory (IMEM)
  *
  * Only 32b-aligned 32b word accesses are allowed.

sw/device/lib/dif/dif_otbn_unittest.cc

diff --git a/sw/device/lib/dif/dif_otbn_unittest.cc b/sw/device/lib/dif/dif_otbn_unittest.cc
index 860e2f4..df216e9 100644
--- a/sw/device/lib/dif/dif_otbn_unittest.cc
+++ b/sw/device/lib/dif/dif_otbn_unittest.cc
@@ -321,6 +321,26 @@
   EXPECT_EQ(err_bits, kDifOtbnErrBitsIllegalInsn | kDifOtbnErrBitsFatalReg);
 }
 
+class GetInsnCntTest : public OtbnTest {};
+
+TEST_F(GetInsnCntTest, NullArgs) {
+  EXPECT_EQ(dif_otbn_get_insn_cnt(nullptr, nullptr), kDifOtbnBadArg);
+
+  EXPECT_EQ(dif_otbn_get_insn_cnt(&dif_otbn_, nullptr), kDifOtbnBadArg);
+
+  uint32_t insn_cnt = 55;
+  EXPECT_EQ(dif_otbn_get_insn_cnt(nullptr, &insn_cnt), kDifOtbnBadArg);
+  EXPECT_EQ(insn_cnt, 55);
+}
+
+TEST_F(GetInsnCntTest, Success) {
+  EXPECT_READ32(OTBN_INSN_CNT_REG_OFFSET, 55);
+
+  uint32_t insn_cnt;
+  EXPECT_EQ(dif_otbn_get_insn_cnt(&dif_otbn_, &insn_cnt), kDifOtbnOk);
+  EXPECT_EQ(insn_cnt, 55);
+}
+
 class ImemWriteTest : public OtbnTest {};
 
 TEST_F(ImemWriteTest, NullArgs) {