1 files changed, 189 insertions, 0 deletions
diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c
new file mode 100644
index 000000000000..1ff1104e6575
--- /dev/null
+++ b/tools/testing/selftests/resctrl/cache.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdint.h>
+#include "resctrl.h"
+
+char llc_occup_path[1024];
+
+void perf_event_attr_initialize(struct perf_event_attr *pea, __u64 config)
+{
+	memset(pea, 0, sizeof(*pea));
+	pea->type = PERF_TYPE_HARDWARE;
+	pea->size = sizeof(*pea);
+	pea->read_format = PERF_FORMAT_GROUP;
+	pea->exclude_kernel = 1;
+	pea->exclude_hv = 1;
+	pea->exclude_idle = 1;
+	pea->exclude_callchain_kernel = 1;
+	pea->inherit = 1;
+	pea->exclude_guest = 1;
+	pea->disabled = 1;
+	pea->config = config;
+}
+
+/* Start counters to log values */
+int perf_event_reset_enable(int pe_fd)
+{
+	int ret;
+
+	ret = ioctl(pe_fd, PERF_EVENT_IOC_RESET, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = ioctl(pe_fd, PERF_EVENT_IOC_ENABLE, 0);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+void perf_event_initialize_read_format(struct perf_event_read *pe_read)
+{
+	memset(pe_read, 0, sizeof(*pe_read));
+	pe_read->nr = 1;
+}
+
+int perf_open(struct perf_event_attr *pea, pid_t pid, int cpu_no)
+{
+	int pe_fd;
+
+	pe_fd = perf_event_open(pea, pid, cpu_no, -1, PERF_FLAG_FD_CLOEXEC);
+	if (pe_fd == -1) {
+		ksft_perror("Error opening leader");
+		return -1;
+	}
+
+	perf_event_reset_enable(pe_fd);
+
+	return pe_fd;
+}
+
+/*
+ * Get LLC Occupancy as reported by RESCTRL FS
+ * For CMT,
+ * 1. If con_mon grp and mon grp given, then read from mon grp in
+ * con_mon grp
+ * 2. If only con_mon grp given, then read from con_mon grp
+ * 3. If both not given, then read from root con_mon grp
+ * For CAT,
+ * 1. If con_mon grp given, then read from it
+ * 2. If con_mon grp not given, then read from root con_mon grp
+ *
+ * Return: =0 on success.  <0 on failure.
+ */
+static int get_llc_occu_resctrl(unsigned long *llc_occupancy)
+{
+	FILE *fp;
+
+	fp = fopen(llc_occup_path, "r");
+	if (!fp) {
+		ksft_perror("Failed to open results file");
+
+		return -1;
+	}
+	if (fscanf(fp, "%lu", llc_occupancy) <= 0) {
+		ksft_perror("Could not get llc occupancy");
+		fclose(fp);
+
+		return -1;
+	}
+	fclose(fp);
+
+	return 0;
+}
+
+/*
+ * print_results_cache:	the cache results are stored in a file
+ * @filename:		file that stores the results
+ * @bm_pid:		child pid that runs benchmark
+ * @llc_value:		perf miss value /
+ *			llc occupancy value reported by resctrl FS
+ *
+ * Return:		0 on success, < 0 on error.
+ */
+static int print_results_cache(const char *filename, pid_t bm_pid, __u64 llc_value)
+{
+	FILE *fp;
+
+	if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
+		printf("Pid: %d \t LLC_value: %llu\n", (int)bm_pid, llc_value);
+	} else {
+		fp = fopen(filename, "a");
+		if (!fp) {
+			ksft_perror("Cannot open results file");
+
+			return -1;
+		}
+		fprintf(fp, "Pid: %d \t llc_value: %llu\n", (int)bm_pid, llc_value);
+		fclose(fp);
+	}
+
+	return 0;
+}
+
+/*
+ * perf_event_measure - Measure perf events
+ * @filename:	Filename for writing the results
+ * @bm_pid:	PID that runs the benchmark
+ *
+ * Measures perf events (e.g., cache misses) and writes the results into
+ * @filename. @bm_pid is written to the results file along with the measured
+ * value.
+ *
+ * Return: =0 on success. <0 on failure.
+ */
+int perf_event_measure(int pe_fd, struct perf_event_read *pe_read,
+		       const char *filename, pid_t bm_pid)
+{
+	int ret;
+
+	/* Stop counters after one span to get miss rate */
+	ret = ioctl(pe_fd, PERF_EVENT_IOC_DISABLE, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = read(pe_fd, pe_read, sizeof(*pe_read));
+	if (ret == -1) {
+		ksft_perror("Could not get perf value");
+		return -1;
+	}
+
+	return print_results_cache(filename, bm_pid, pe_read->values[0].value);
+}
+
+/*
+ * measure_llc_resctrl - Measure resctrl LLC value from resctrl
+ * @filename:	Filename for writing the results
+ * @bm_pid:	PID that runs the benchmark
+ *
+ * Measures LLC occupancy from resctrl and writes the results into @filename.
+ * @bm_pid is written to the results file along with the measured value.
+ *
+ * Return: =0 on success. <0 on failure.
+ */
+int measure_llc_resctrl(const char *filename, pid_t bm_pid)
+{
+	unsigned long llc_occu_resc = 0;
+	int ret;
+
+	ret = get_llc_occu_resctrl(&llc_occu_resc);
+	if (ret < 0)
+		return ret;
+
+	return print_results_cache(filename, bm_pid, llc_occu_resc);
+}
+
+/*
+ * show_cache_info - Show generic cache test information
+ * @no_of_bits:		Number of bits
+ * @avg_llc_val:	Average of LLC cache result data
+ * @cache_span:		Cache span
+ * @lines:		@cache_span in lines or bytes
+ */
+void show_cache_info(int no_of_bits, __u64 avg_llc_val, size_t cache_span, bool lines)
+{
+	ksft_print_msg("Number of bits: %d\n", no_of_bits);
+	ksft_print_msg("Average LLC val: %llu\n", avg_llc_val);
+	ksft_print_msg("Cache span (%s): %zu\n", lines ? "lines" : "bytes",
+		       cache_span);
+}