1// SPDX-License-Identifier: GPL-2.0
  2
  3#include <stdint.h>
  4#include "resctrl.h"
  5
  6char llc_occup_path[1024];
  7
  8void perf_event_attr_initialize(struct perf_event_attr *pea, __u64 config)
  9{
 10	memset(pea, 0, sizeof(*pea));
 11	pea->type = PERF_TYPE_HARDWARE;
 12	pea->size = sizeof(*pea);
 13	pea->read_format = PERF_FORMAT_GROUP;
 14	pea->exclude_kernel = 1;
 15	pea->exclude_hv = 1;
 16	pea->exclude_idle = 1;
 17	pea->exclude_callchain_kernel = 1;
 18	pea->inherit = 1;
 19	pea->exclude_guest = 1;
 20	pea->disabled = 1;
 21	pea->config = config;
 22}
 23
 24/* Start counters to log values */
 25int perf_event_reset_enable(int pe_fd)
 26{
 27	int ret;
 28
 29	ret = ioctl(pe_fd, PERF_EVENT_IOC_RESET, 0);
 30	if (ret < 0)
 31		return ret;
 32
 33	ret = ioctl(pe_fd, PERF_EVENT_IOC_ENABLE, 0);
 34	if (ret < 0)
 35		return ret;
 36
 37	return 0;
 38}
 39
 40void perf_event_initialize_read_format(struct perf_event_read *pe_read)
 41{
 42	memset(pe_read, 0, sizeof(*pe_read));
 43	pe_read->nr = 1;
 44}
 45
 46int perf_open(struct perf_event_attr *pea, pid_t pid, int cpu_no)
 47{
 48	int pe_fd;
 49
 50	pe_fd = perf_event_open(pea, pid, cpu_no, -1, PERF_FLAG_FD_CLOEXEC);
 51	if (pe_fd == -1) {
 52		ksft_perror("Error opening leader");
 53		return -1;
 54	}
 55
 56	perf_event_reset_enable(pe_fd);
 57
 58	return pe_fd;
 59}
 60
 61/*
 62 * Get LLC Occupancy as reported by RESCTRL FS
 63 * For CMT,
 64 * 1. If con_mon grp and mon grp given, then read from mon grp in
 65 * con_mon grp
 66 * 2. If only con_mon grp given, then read from con_mon grp
 67 * 3. If both not given, then read from root con_mon grp
 68 * For CAT,
 69 * 1. If con_mon grp given, then read from it
 70 * 2. If con_mon grp not given, then read from root con_mon grp
 71 *
 72 * Return: =0 on success.  <0 on failure.
 73 */
 74static int get_llc_occu_resctrl(unsigned long *llc_occupancy)
 75{
 76	FILE *fp;
 77
 78	fp = fopen(llc_occup_path, "r");
 79	if (!fp) {
 80		ksft_perror("Failed to open results file");
 81
 82		return -1;
 83	}
 84	if (fscanf(fp, "%lu", llc_occupancy) <= 0) {
 85		ksft_perror("Could not get llc occupancy");
 86		fclose(fp);
 87
 88		return -1;
 89	}
 90	fclose(fp);
 91
 92	return 0;
 93}
 94
 95/*
 96 * print_results_cache:	the cache results are stored in a file
 97 * @filename:		file that stores the results
 98 * @bm_pid:		child pid that runs benchmark
 99 * @llc_value:		perf miss value /
100 *			llc occupancy value reported by resctrl FS
101 *
102 * Return:		0 on success, < 0 on error.
103 */
104static int print_results_cache(const char *filename, pid_t bm_pid, __u64 llc_value)
105{
106	FILE *fp;
107
108	if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
109		printf("Pid: %d \t LLC_value: %llu\n", (int)bm_pid, llc_value);
110	} else {
111		fp = fopen(filename, "a");
112		if (!fp) {
113			ksft_perror("Cannot open results file");
114
115			return -1;
116		}
117		fprintf(fp, "Pid: %d \t llc_value: %llu\n", (int)bm_pid, llc_value);
118		fclose(fp);
119	}
120
121	return 0;
122}
123
124/*
125 * perf_event_measure - Measure perf events
126 * @filename:	Filename for writing the results
127 * @bm_pid:	PID that runs the benchmark
128 *
129 * Measures perf events (e.g., cache misses) and writes the results into
130 * @filename. @bm_pid is written to the results file along with the measured
131 * value.
132 *
133 * Return: =0 on success. <0 on failure.
134 */
135int perf_event_measure(int pe_fd, struct perf_event_read *pe_read,
136		       const char *filename, pid_t bm_pid)
137{
138	int ret;
139
140	/* Stop counters after one span to get miss rate */
141	ret = ioctl(pe_fd, PERF_EVENT_IOC_DISABLE, 0);
142	if (ret < 0)
143		return ret;
144
145	ret = read(pe_fd, pe_read, sizeof(*pe_read));
146	if (ret == -1) {
147		ksft_perror("Could not get perf value");
148		return -1;
149	}
150
151	return print_results_cache(filename, bm_pid, pe_read->values[0].value);
152}
153
154/*
155 * measure_llc_resctrl - Measure resctrl LLC value from resctrl
156 * @filename:	Filename for writing the results
157 * @bm_pid:	PID that runs the benchmark
158 *
159 * Measures LLC occupancy from resctrl and writes the results into @filename.
160 * @bm_pid is written to the results file along with the measured value.
161 *
162 * Return: =0 on success. <0 on failure.
163 */
164int measure_llc_resctrl(const char *filename, pid_t bm_pid)
165{
166	unsigned long llc_occu_resc = 0;
167	int ret;
168
169	ret = get_llc_occu_resctrl(&llc_occu_resc);
170	if (ret < 0)
171		return ret;
172
173	return print_results_cache(filename, bm_pid, llc_occu_resc);
174}
175
176/*
177 * show_cache_info - Show generic cache test information
178 * @no_of_bits:		Number of bits
179 * @avg_llc_val:	Average of LLC cache result data
180 * @cache_span:		Cache span
181 * @lines:		@cache_span in lines or bytes
182 */
183void show_cache_info(int no_of_bits, __u64 avg_llc_val, size_t cache_span, bool lines)
184{
185	ksft_print_msg("Number of bits: %d\n", no_of_bits);
186	ksft_print_msg("Average LLC val: %llu\n", avg_llc_val);
187	ksft_print_msg("Cache span (%s): %zu\n", lines ? "lines" : "bytes",
188		       cache_span);
189}