selftests/resctrl: Add basic resctrl file system operations and data

The basic resctrl file system operations and data are added for future
usage by resctrl selftest tool.
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/Makefile

+CC = $(CROSS_COMPILE)gcc
+CFLAGS = -g -Wall
+SRCS=$(wildcard *.c)
+OBJS=$(SRCS:.c=.o)
+
+$(OBJS): $(SRCS)
+	$(CC) $(CFLAGS) -c $(SRCS)
+
+.PHONY: clean
+
+clean:
+	$(RM) $(OBJS)

tools/testing/selftests/resctrl/resctrl.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#define _GNU_SOURCE
+#ifndef RESCTRL_H
+#define RESCTRL_H
+#include <stdio.h>
+#include <errno.h>
+#include <sched.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <signal.h>
+#include <dirent.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <asm/unistd.h>
+#include <linux/perf_event.h>
+
+#define RESCTRL_PATH		"/sys/fs/resctrl"
+#define PHYS_ID_PATH		"/sys/devices/system/cpu/cpu"
+
+#define PARENT_EXIT(err_msg)			\
+	do {					\
+		perror(err_msg);		\
+		kill(ppid, SIGKILL);		\
+		exit(EXIT_FAILURE);		\
+	} while (0)
+
+pid_t bm_pid, ppid;
+
+int remount_resctrlfs(bool mum_resctrlfs);
+int get_resource_id(int cpu_no, int *resource_id);
+int validate_bw_report_request(char *bw_report);
+bool validate_resctrl_feature_request(char *resctrl_val);
+char *fgrep(FILE *inf, const char *str);
+int taskset_benchmark(pid_t bm_pid, int cpu_no);
+void run_benchmark(int signum, siginfo_t *info, void *ucontext);
+int write_schemata(char *ctrlgrp, char *schemata, int cpu_no,
+		   char *resctrl_val);
+int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
+			    char *resctrl_val);
+int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
+		    int group_fd, unsigned long flags);
+int run_fill_buf(unsigned long span, int malloc_and_init_memory, int memflush,
+		 int op, char *resctrl_va);
+
+#endif /* RESCTRL_H */