selftests/resctrl: Read memory bandwidth from perf IMC counter and from resctrl file system

Total memory bandwidth can be monitored from perf IMC counter and from
resctrl file system. Later the two will be compared to verify the total
memory bandwidth read from resctrl is correct.
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Co-developed-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/resctrl/resctrl_val.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Memory bandwidth monitoring and allocation library
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * Authors:
+ *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
+ *    Fenghua Yu <fenghua.yu@intel.com>
+ */
+#include "resctrl.h"
+
+#define UNCORE_IMC		"uncore_imc"
+#define READ_FILE_NAME		"events/cas_count_read"
+#define WRITE_FILE_NAME		"events/cas_count_write"
+#define DYN_PMU_PATH		"/sys/bus/event_source/devices"
+#define SCALE			0.00006103515625
+#define MAX_IMCS		20
+#define MAX_TOKENS		5
+#define READ			0
+#define WRITE			1
+#define CON_MON_MBM_LOCAL_BYTES_PATH				\
+	"%s/%s/mon_groups/%s/mon_data/mon_L3_%02d/mbm_local_bytes"
+
+#define CON_MBM_LOCAL_BYTES_PATH		\
+	"%s/%s/mon_data/mon_L3_%02d/mbm_local_bytes"
+
+#define MON_MBM_LOCAL_BYTES_PATH		\
+	"%s/mon_groups/%s/mon_data/mon_L3_%02d/mbm_local_bytes"
+
+#define MBM_LOCAL_BYTES_PATH			\
+	"%s/mon_data/mon_L3_%02d/mbm_local_bytes"
+
+struct membw_read_format {
+	__u64 value;         /* The value of the event */
+	__u64 time_enabled;  /* if PERF_FORMAT_TOTAL_TIME_ENABLED */
+	__u64 time_running;  /* if PERF_FORMAT_TOTAL_TIME_RUNNING */
+	__u64 id;            /* if PERF_FORMAT_ID */
+};
+
+struct imc_counter_config {
+	__u32 type;
+	__u64 event;
+	__u64 umask;
+	struct perf_event_attr pe;
+	struct membw_read_format return_value;
+	int fd;
+};
+
+static struct imc_counter_config imc_counters_config[MAX_IMCS][2];
+
+void membw_initialize_perf_event_attr(int i, int j)
+{
+	memset(&imc_counters_config[i][j].pe, 0,
+	       sizeof(struct perf_event_attr));
+	imc_counters_config[i][j].pe.type = imc_counters_config[i][j].type;
+	imc_counters_config[i][j].pe.size = sizeof(struct perf_event_attr);
+	imc_counters_config[i][j].pe.disabled = 1;
+	imc_counters_config[i][j].pe.inherit = 1;
+	imc_counters_config[i][j].pe.exclude_guest = 0;
+	imc_counters_config[i][j].pe.config =
+		imc_counters_config[i][j].umask << 8 |
+		imc_counters_config[i][j].event;
+	imc_counters_config[i][j].pe.sample_type = PERF_SAMPLE_IDENTIFIER;
+	imc_counters_config[i][j].pe.read_format =
+		PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING;
+}
+
+void membw_ioctl_perf_event_ioc_reset_enable(int i, int j)
+{
+	ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_RESET, 0);
+	ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_ENABLE, 0);
+}
+
+void membw_ioctl_perf_event_ioc_disable(int i, int j)
+{
+	ioctl(imc_counters_config[i][j].fd, PERF_EVENT_IOC_DISABLE, 0);
+}
+
+/*
+ * get_event_and_umask:	Parse config into event and umask
+ * @cas_count_cfg:	Config
+ * @count:		iMC number
+ * @op:			Operation (read/write)
+ */
+void get_event_and_umask(char *cas_count_cfg, int count, bool op)
+{
+	char *token[MAX_TOKENS];
+	int i = 0;
+
+	strcat(cas_count_cfg, ",");
+	token[0] = strtok(cas_count_cfg, "=,");
+
+	for (i = 1; i < MAX_TOKENS; i++)
+		token[i] = strtok(NULL, "=,");
+
+	for (i = 0; i < MAX_TOKENS; i++) {
+		if (!token[i])
+			break;
+		if (strcmp(token[i], "event") == 0) {
+			if (op == READ)
+				imc_counters_config[count][READ].event =
+				strtol(token[i + 1], NULL, 16);
+			else
+				imc_counters_config[count][WRITE].event =
+				strtol(token[i + 1], NULL, 16);
+		}
+		if (strcmp(token[i], "umask") == 0) {
+			if (op == READ)
+				imc_counters_config[count][READ].umask =
+				strtol(token[i + 1], NULL, 16);
+			else
+				imc_counters_config[count][WRITE].umask =
+				strtol(token[i + 1], NULL, 16);
+		}
+	}
+}