Add perf_counters test
- At the moment, this only tests mcycle / mcycleh. As Kelvin gets more
perf counters, we can expand this test suite.
Change-Id: Ia96b183ffd323fa9333bfa3792aa051e66714a84
diff --git a/tests/kelvin_isa/BUILD b/tests/kelvin_isa/BUILD
index 52865ac..1584d83 100644
--- a/tests/kelvin_isa/BUILD
+++ b/tests/kelvin_isa/BUILD
@@ -25,6 +25,17 @@
)
kelvin_test(
+ name = "perf_counters",
+ srcs = [
+ "perf_counters.cc",
+ ],
+ hw_test_size = "small",
+ deps = [
+ ":kelvin_test",
+ ],
+)
+
+kelvin_test(
name = "acset",
srcs = [
"acset.cc",
diff --git a/tests/kelvin_isa/perf_counters.cc b/tests/kelvin_isa/perf_counters.cc
new file mode 100644
index 0000000..937f820
--- /dev/null
+++ b/tests/kelvin_isa/perf_counters.cc
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <cstdio>
+#include <cstdint>
+
+#include "tests/kelvin_isa/kelvin_test.h"
+
+inline uint64_t mcycle_read(void) {
+ uint32_t cycle_low = 0;
+ uint32_t cycle_high = 0;
+ asm volatile(
+ "1:"
+ " csrr %0, mcycleh;" // Read `mcycleh`.
+ " csrr %1, mcycle;" // Read `mcycle`.
+ : "=r"(cycle_high), "=r"(cycle_low)
+ :);
+ return static_cast<uint64_t>(cycle_high) << 32 | cycle_low;
+}
+
+int main(void) {
+ // Set the cycle counter to 0x1ffffffff.
+ asm volatile (" \
+ csrwi mcycleh, 1; \
+ li a0, 0xfffffffd; \
+ csrrw a0, mcycle, a0;" : /* no outputs*/ : /* no inputs */ : /* clobbers */"a0");
+ uint64_t cycle = mcycle_read();
+ uint64_t cycle2 = mcycle_read();
+ uint32_t cycle_lo, cycle_hi, cycle2_lo, cycle2_hi;
+ cycle_lo = cycle & 0xFFFFFFFF;
+ cycle2_lo = cycle2 & 0xFFFFFFFF;
+ cycle_hi = cycle >> 32;
+ cycle2_hi = cycle2 >> 32;
+ if (cycle2_hi == cycle_hi) {
+ printf("mcycleh did not increment\r\n");
+ exit(-1);
+ }
+ if (cycle2_lo > cycle_lo) {
+ printf("mcycle did not wrap");
+ exit(-1);
+ }
+ return 0;
+}
