1 files changed, 314 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..68ff856d36f0
--- /dev/null
+++ b/tools/testing/selftests/resctrl/cache.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdint.h>
+#include "resctrl.h"
+
+struct read_format {
+	__u64 nr;			/* The number of events */
+	struct {
+		__u64 value;		/* The value of the event */
+	} values[2];
+};
+
+static struct perf_event_attr pea_llc_miss;
+static struct read_format rf_cqm;
+static int fd_lm;
+char llc_occup_path[1024];
+
+static void initialize_perf_event_attr(void)
+{
+	pea_llc_miss.type = PERF_TYPE_HARDWARE;
+	pea_llc_miss.size = sizeof(struct perf_event_attr);
+	pea_llc_miss.read_format = PERF_FORMAT_GROUP;
+	pea_llc_miss.exclude_kernel = 1;
+	pea_llc_miss.exclude_hv = 1;
+	pea_llc_miss.exclude_idle = 1;
+	pea_llc_miss.exclude_callchain_kernel = 1;
+	pea_llc_miss.inherit = 1;
+	pea_llc_miss.exclude_guest = 1;
+	pea_llc_miss.disabled = 1;
+}
+
+static void ioctl_perf_event_ioc_reset_enable(void)
+{
+	ioctl(fd_lm, PERF_EVENT_IOC_RESET, 0);
+	ioctl(fd_lm, PERF_EVENT_IOC_ENABLE, 0);
+}
+
+static int perf_event_open_llc_miss(pid_t pid, int cpu_no)
+{
+	fd_lm = perf_event_open(&pea_llc_miss, pid, cpu_no, -1,
+				PERF_FLAG_FD_CLOEXEC);
+	if (fd_lm == -1) {
+		perror("Error opening leader");
+		ctrlc_handler(0, NULL, NULL);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int initialize_llc_perf(void)
+{
+	memset(&pea_llc_miss, 0, sizeof(struct perf_event_attr));
+	memset(&rf_cqm, 0, sizeof(struct read_format));
+
+	/* Initialize perf_event_attr structures for HW_CACHE_MISSES */
+	initialize_perf_event_attr();
+
+	pea_llc_miss.config = PERF_COUNT_HW_CACHE_MISSES;
+
+	rf_cqm.nr = 1;
+
+	return 0;
+}
+
+static int reset_enable_llc_perf(pid_t pid, int cpu_no)
+{
+	int ret = 0;
+
+	ret = perf_event_open_llc_miss(pid, cpu_no);
+	if (ret < 0)
+		return ret;
+
+	/* Start counters to log values */
+	ioctl_perf_event_ioc_reset_enable();
+
+	return 0;
+}
+
+/*
+ * get_llc_perf:	llc cache miss through perf events
+ * @cpu_no:		CPU number that the benchmark PID is binded to
+ *
+ * Perf events like HW_CACHE_MISSES could be used to validate number of
+ * cache lines allocated.
+ *
+ * Return: =0 on success.  <0 on failure.
+ */
+static int get_llc_perf(unsigned long *llc_perf_miss)
+{
+	__u64 total_misses;
+
+	/* Stop counters after one span to get miss rate */
+
+	ioctl(fd_lm, PERF_EVENT_IOC_DISABLE, 0);
+
+	if (read(fd_lm, &rf_cqm, sizeof(struct read_format)) == -1) {
+		perror("Could not get llc misses through perf");
+
+		return -1;
+	}
+
+	total_misses = rf_cqm.values[0].value;
+
+	close(fd_lm);
+
+	*llc_perf_miss = total_misses;
+
+	return 0;
+}
+
+/*
+ * 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) {
+		perror("Failed to open results file");
+
+		return errno;
+	}
+	if (fscanf(fp, "%lu", llc_occupancy) <= 0) {
+		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. non-zero on failure.
+ */
+static int print_results_cache(char *filename, int bm_pid,
+			       unsigned long llc_value)
+{
+	FILE *fp;
+
+	if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
+		printf("Pid: %d \t LLC_value: %lu\n", bm_pid,
+		       llc_value);
+	} else {
+		fp = fopen(filename, "a");
+		if (!fp) {
+			perror("Cannot open results file");
+
+			return errno;
+		}
+		fprintf(fp, "Pid: %d \t llc_value: %lu\n", bm_pid, llc_value);
+		fclose(fp);
+	}
+
+	return 0;
+}
+
+int measure_cache_vals(struct resctrl_val_param *param, int bm_pid)
+{
+	unsigned long llc_perf_miss = 0, llc_occu_resc = 0, llc_value = 0;
+	int ret;
+
+	/*
+	 * Measure cache miss from perf.
+	 */
+	if (!strncmp(param->resctrl_val, CAT_STR, sizeof(CAT_STR))) {
+		ret = get_llc_perf(&llc_perf_miss);
+		if (ret < 0)
+			return ret;
+		llc_value = llc_perf_miss;
+	}
+
+	/*
+	 * Measure llc occupancy from resctrl.
+	 */
+	if (!strncmp(param->resctrl_val, CMT_STR, sizeof(CMT_STR))) {
+		ret = get_llc_occu_resctrl(&llc_occu_resc);
+		if (ret < 0)
+			return ret;
+		llc_value = llc_occu_resc;
+	}
+	ret = print_results_cache(param->filename, bm_pid, llc_value);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * cache_val:		execute benchmark and measure LLC occupancy resctrl
+ * and perf cache miss for the benchmark
+ * @param:		parameters passed to cache_val()
+ *
+ * Return:		0 on success. non-zero on failure.
+ */
+int cat_val(struct resctrl_val_param *param)
+{
+	int malloc_and_init_memory = 1, memflush = 1, operation = 0, ret = 0;
+	char *resctrl_val = param->resctrl_val;
+	pid_t bm_pid;
+
+	if (strcmp(param->filename, "") == 0)
+		sprintf(param->filename, "stdio");
+
+	bm_pid = getpid();
+
+	/* Taskset benchmark to specified cpu */
+	ret = taskset_benchmark(bm_pid, param->cpu_no);
+	if (ret)
+		return ret;
+
+	/* Write benchmark to specified con_mon grp, mon_grp in resctrl FS*/
+	ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp,
+				      resctrl_val);
+	if (ret)
+		return ret;
+
+	if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR))) {
+		ret = initialize_llc_perf();
+		if (ret)
+			return ret;
+	}
+
+	/* Test runs until the callback setup() tells the test to stop. */
+	while (1) {
+		if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR))) {
+			ret = param->setup(1, param);
+			if (ret) {
+				ret = 0;
+				break;
+			}
+			ret = reset_enable_llc_perf(bm_pid, param->cpu_no);
+			if (ret)
+				break;
+
+			if (run_fill_buf(param->span, malloc_and_init_memory,
+					 memflush, operation, resctrl_val)) {
+				fprintf(stderr, "Error-running fill buffer\n");
+				ret = -1;
+				break;
+			}
+
+			sleep(1);
+			ret = measure_cache_vals(param, bm_pid);
+			if (ret)
+				break;
+		} else {
+			break;
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * show_cache_info:	show cache test result information
+ * @sum_llc_val:	sum of LLC cache result data
+ * @no_of_bits:		number of bits
+ * @cache_span:		cache span in bytes for CMT or in lines for CAT
+ * @max_diff:		max difference
+ * @max_diff_percent:	max difference percentage
+ * @num_of_runs:	number of runs
+ * @platform:		show test information on this platform
+ * @cmt:		CMT test or CAT test
+ *
+ * Return:		0 on success. non-zero on failure.
+ */
+int show_cache_info(unsigned long sum_llc_val, int no_of_bits,
+		    unsigned long cache_span, unsigned long max_diff,
+		    unsigned long max_diff_percent, unsigned long num_of_runs,
+		    bool platform, bool cmt)
+{
+	unsigned long avg_llc_val = 0;
+	float diff_percent;
+	long avg_diff = 0;
+	int ret;
+
+	avg_llc_val = sum_llc_val / (num_of_runs - 1);
+	avg_diff = (long)abs(cache_span - avg_llc_val);
+	diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100;
+
+	ret = platform && abs((int)diff_percent) > max_diff_percent &&
+	      (cmt ? (abs(avg_diff) > max_diff) : true);
+
+	ksft_print_msg("%s Check cache miss rate within %d%%\n",
+		       ret ? "Fail:" : "Pass:", max_diff_percent);
+
+	ksft_print_msg("Percent diff=%d\n", abs((int)diff_percent));
+	ksft_print_msg("Number of bits: %d\n", no_of_bits);
+	ksft_print_msg("Average LLC val: %lu\n", avg_llc_val);
+	ksft_print_msg("Cache span (%s): %lu\n", cmt ? "bytes" : "lines",
+		       cache_span);
+
+	return ret;
+}