1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Cache Allocation Technology (CAT) test
  4 *
  5 * Copyright (C) 2018 Intel Corporation
  6 *
  7 * Authors:
  8 *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
  9 *    Fenghua Yu <fenghua.yu@intel.com>
 10 */
 11#include "resctrl.h"
 12#include <unistd.h>
 13
 14#define RESULT_FILE_NAME1	"result_cat1"
 15#define RESULT_FILE_NAME2	"result_cat2"
 16#define NUM_OF_RUNS		5
 17#define MAX_DIFF_PERCENT	4
 18#define MAX_DIFF		1000000
 19
 20int count_of_bits;
 21char cbm_mask[256];
 22unsigned long long_mask;
 23unsigned long cache_size;
 24
 25/*
 26 * Change schemata. Write schemata to specified
 27 * con_mon grp, mon_grp in resctrl FS.
 28 * Run 5 times in order to get average values.
 29 */
 30static int cat_setup(int num, ...)
 31{
 32	struct resctrl_val_param *p;
 33	char schemata[64];
 34	va_list param;
 35	int ret = 0;
 36
 37	va_start(param, num);
 38	p = va_arg(param, struct resctrl_val_param *);
 39	va_end(param);
 40
 41	/* Run NUM_OF_RUNS times */
 42	if (p->num_of_runs >= NUM_OF_RUNS)
 43		return -1;
 44
 45	if (p->num_of_runs == 0) {
 46		sprintf(schemata, "%lx", p->mask);
 47		ret = write_schemata(p->ctrlgrp, schemata, p->cpu_no,
 48				     p->resctrl_val);
 49	}
 50	p->num_of_runs++;
 51
 52	return ret;
 53}
 54
 55static void show_cache_info(unsigned long sum_llc_perf_miss, int no_of_bits,
 56			    unsigned long span)
 57{
 58	unsigned long allocated_cache_lines = span / 64;
 59	unsigned long avg_llc_perf_miss = 0;
 60	float diff_percent;
 61
 62	avg_llc_perf_miss = sum_llc_perf_miss / (NUM_OF_RUNS - 1);
 63	diff_percent = ((float)allocated_cache_lines - avg_llc_perf_miss) /
 64				allocated_cache_lines * 100;
 65
 66	printf("%sok CAT: cache miss rate within %d%%\n",
 67	       !is_amd && abs((int)diff_percent) > MAX_DIFF_PERCENT ?
 68	       "not " : "", MAX_DIFF_PERCENT);
 69	tests_run++;
 70	printf("# Percent diff=%d\n", abs((int)diff_percent));
 71	printf("# Number of bits: %d\n", no_of_bits);
 72	printf("# Avg_llc_perf_miss: %lu\n", avg_llc_perf_miss);
 73	printf("# Allocated cache lines: %lu\n", allocated_cache_lines);
 74}
 75
 76static int check_results(struct resctrl_val_param *param)
 77{
 78	char *token_array[8], temp[512];
 79	unsigned long sum_llc_perf_miss = 0;
 80	int runs = 0, no_of_bits = 0;
 81	FILE *fp;
 82
 83	printf("# Checking for pass/fail\n");
 84	fp = fopen(param->filename, "r");
 85	if (!fp) {
 86		perror("# Cannot open file");
 87
 88		return errno;
 89	}
 90
 91	while (fgets(temp, sizeof(temp), fp)) {
 92		char *token = strtok(temp, ":\t");
 93		int fields = 0;
 94
 95		while (token) {
 96			token_array[fields++] = token;
 97			token = strtok(NULL, ":\t");
 98		}
 99		/*
100		 * Discard the first value which is inaccurate due to monitoring
101		 * setup transition phase.
102		 */
103		if (runs > 0)
104			sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
105		runs++;
106	}
107
108	fclose(fp);
109	no_of_bits = count_bits(param->mask);
110
111	show_cache_info(sum_llc_perf_miss, no_of_bits, param->span);
112
113	return 0;
114}
115
116void cat_test_cleanup(void)
117{
118	remove(RESULT_FILE_NAME1);
119	remove(RESULT_FILE_NAME2);
120}
121
122int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
123{
124	unsigned long l_mask, l_mask_1;
125	int ret, pipefd[2], sibling_cpu_no;
126	char pipe_message;
127	pid_t bm_pid;
128
129	cache_size = 0;
130
131	ret = remount_resctrlfs(true);
132	if (ret)
133		return ret;
134
135	if (!validate_resctrl_feature_request("cat"))
136		return -1;
137
138	/* Get default cbm mask for L3/L2 cache */
139	ret = get_cbm_mask(cache_type);
140	if (ret)
141		return ret;
142
143	long_mask = strtoul(cbm_mask, NULL, 16);
144
145	/* Get L3/L2 cache size */
146	ret = get_cache_size(cpu_no, cache_type, &cache_size);
147	if (ret)
148		return ret;
149	printf("cache size :%lu\n", cache_size);
150
151	/* Get max number of bits from default-cabm mask */
152	count_of_bits = count_bits(long_mask);
153
154	if (n < 1 || n > count_of_bits - 1) {
155		printf("Invalid input value for no_of_bits n!\n");
156		printf("Please Enter value in range 1 to %d\n",
157		       count_of_bits - 1);
158		return -1;
159	}
160
161	/* Get core id from same socket for running another thread */
162	sibling_cpu_no = get_core_sibling(cpu_no);
163	if (sibling_cpu_no < 0)
164		return -1;
165
166	struct resctrl_val_param param = {
167		.resctrl_val	= "cat",
168		.cpu_no		= cpu_no,
169		.mum_resctrlfs	= 0,
170		.setup		= cat_setup,
171	};
172
173	l_mask = long_mask >> n;
174	l_mask_1 = ~l_mask & long_mask;
175
176	/* Set param values for parent thread which will be allocated bitmask
177	 * with (max_bits - n) bits
178	 */
179	param.span = cache_size * (count_of_bits - n) / count_of_bits;
180	strcpy(param.ctrlgrp, "c2");
181	strcpy(param.mongrp, "m2");
182	strcpy(param.filename, RESULT_FILE_NAME2);
183	param.mask = l_mask;
184	param.num_of_runs = 0;
185
186	if (pipe(pipefd)) {
187		perror("# Unable to create pipe");
188		return errno;
189	}
190
191	bm_pid = fork();
192
193	/* Set param values for child thread which will be allocated bitmask
194	 * with n bits
195	 */
196	if (bm_pid == 0) {
197		param.mask = l_mask_1;
198		strcpy(param.ctrlgrp, "c1");
199		strcpy(param.mongrp, "m1");
200		param.span = cache_size * n / count_of_bits;
201		strcpy(param.filename, RESULT_FILE_NAME1);
202		param.num_of_runs = 0;
203		param.cpu_no = sibling_cpu_no;
204	}
205
206	remove(param.filename);
207
208	ret = cat_val(&param);
209	if (ret)
210		return ret;
211
212	ret = check_results(&param);
213	if (ret)
214		return ret;
215
216	if (bm_pid == 0) {
217		/* Tell parent that child is ready */
218		close(pipefd[0]);
219		pipe_message = 1;
220		if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
221		    sizeof(pipe_message)) {
222			close(pipefd[1]);
223			perror("# failed signaling parent process");
224			return errno;
225		}
226
227		close(pipefd[1]);
228		while (1)
229			;
230	} else {
231		/* Parent waits for child to be ready. */
232		close(pipefd[1]);
233		pipe_message = 0;
234		while (pipe_message != 1) {
235			if (read(pipefd[0], &pipe_message,
236				 sizeof(pipe_message)) < sizeof(pipe_message)) {
237				perror("# failed reading from child process");
238				break;
239			}
240		}
241		close(pipefd[0]);
242		kill(bm_pid, SIGKILL);
243	}
244
245	cat_test_cleanup();
246	if (bm_pid)
247		umount_resctrlfs();
248
249	return 0;
250}