/* SPDX-License-Identifier: GPL-2.0 */
#ifndef RESCTRL_H
#define RESCTRL_H
#include <stdio.h>
#include <math.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 <ctype.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/select.h>
#include <sys/time.h>
#include <sys/eventfd.h>
#include <asm/unistd.h>
#include <linux/perf_event.h>
#include <linux/compiler.h>
#include <linux/bits.h>
#include "kselftest.h"

#define MB                      (1024 * 1024)
#define RESCTRL_PATH            "/sys/fs/resctrl"
#define PHYS_ID_PATH            "/sys/devices/system/cpu/cpu"
#define INFO_PATH               "/sys/fs/resctrl/info"

/*
 * CPU vendor IDs
 *
 * Define as bits because they're used for vendor_specific bitmask in
 * the struct resctrl_test.
 */
#define ARCH_INTEL      BIT(0)
#define ARCH_AMD        BIT(1)
#define ARCH_HYGON      BIT(2)

#define END_OF_TESTS    1

#define BENCHMARK_ARGS          64

#define MINIMUM_SPAN            (250 * MB)

/*
 * Memory bandwidth (in MiB) below which the bandwidth comparisons
 * between iMC and resctrl are considered unreliable. For example RAS
 * features or memory performance features that generate memory traffic
 * may drive accesses that are counted differently by performance counters
 * and MBM respectively, for instance generating "overhead" traffic which
 * is not counted against any specific RMID.
 */
#define THROTTLE_THRESHOLD      750

/*
 * fill_buf_param:      "fill_buf" benchmark parameters
 * @buf_size:           Size (in bytes) of buffer used in benchmark.
 *                      "fill_buf" allocates and initializes buffer of
 *                      @buf_size. User can change value via command line.
 * @memflush:           If false the buffer will not be flushed after
 *                      allocation and initialization, otherwise the
 *                      buffer will be flushed. User can change value via
 *                      command line (via integers with 0 interpreted as
 *                      false and anything else as true).
 */
struct fill_buf_param {
        size_t          buf_size;
        bool            memflush;
};

/*
 * user_params:         User supplied parameters
 * @cpu:                CPU number to which the benchmark will be bound to
 * @bits:               Number of bits used for cache allocation size
 * @benchmark_cmd:      Benchmark command to run during (some of the) tests
 * @fill_buf:           Pointer to user provided parameters for "fill_buf",
 *                      NULL if user did not provide parameters and test
 *                      specific defaults should be used.
 */
struct user_params {
        int cpu;
        int bits;
        const char *benchmark_cmd[BENCHMARK_ARGS];
        const struct fill_buf_param *fill_buf;
};

/*
 * resctrl_test:        resctrl test definition
 * @name:               Test name
 * @group:              Test group - a common name for tests that share some characteristic
 *                      (e.g., L3 CAT test belongs to the CAT group). Can be NULL
 * @resource:           Resource to test (e.g., MB, L3, L2, etc.)
 * @vendor_specific:    Bitmask for vendor-specific tests (can be 0 for universal tests)
 * @disabled:           Test is disabled
 * @feature_check:      Callback to check required resctrl features
 * @run_test:           Callback to run the test
 * @cleanup:            Callback to cleanup after the test
 */
struct resctrl_test {
        const char      *name;
        const char      *group;
        const char      *resource;
        unsigned int    vendor_specific;
        bool            disabled;
        bool            (*feature_check)(const struct resctrl_test *test);
        int             (*run_test)(const struct resctrl_test *test,
                                    const struct user_params *uparams);
        void            (*cleanup)(void);
};

/*
 * resctrl_val_param:   resctrl test parameters
 * @ctrlgrp:            Name of the control monitor group (con_mon grp)
 * @mongrp:             Name of the monitor group (mon grp)
 * @filename:           Name of file to which the o/p should be written
 * @init:               Callback function to initialize test environment
 * @setup:              Callback function to setup per test run environment
 * @measure:            Callback that performs the measurement (a single test)
 * @fill_buf:           Parameters for default "fill_buf" benchmark.
 *                      Initialized with user provided parameters, possibly
 *                      adapted to be relevant to the test. If user does
 *                      not provide parameters for "fill_buf" nor a
 *                      replacement benchmark then initialized with defaults
 *                      appropriate for test. NULL if user provided
 *                      benchmark.
 */
struct resctrl_val_param {
        const char              *ctrlgrp;
        const char              *mongrp;
        char                    filename[64];
        unsigned long           mask;
        int                     num_of_runs;
        int                     (*init)(const struct resctrl_val_param *param,
                                        int domain_id);
        int                     (*setup)(const struct resctrl_test *test,
                                         const struct user_params *uparams,
                                         struct resctrl_val_param *param);
        int                     (*measure)(const struct user_params *uparams,
                                           struct resctrl_val_param *param,
                                           pid_t bm_pid);
        struct fill_buf_param   *fill_buf;
};

struct perf_event_read {
        __u64 nr;                       /* The number of events */
        struct {
                __u64 value;            /* The value of the event */
        } values[2];
};

/*
 * Memory location that consumes values compiler must not optimize away.
 * Volatile ensures writes to this location cannot be optimized away by
 * compiler.
 */
extern volatile int *value_sink;

extern int snc_unreliable;

extern char llc_occup_path[1024];

int snc_nodes_per_l3_cache(void);
unsigned int get_vendor(void);
bool check_resctrlfs_support(void);
int filter_dmesg(void);
int get_domain_id(const char *resource, int cpu_no, int *domain_id);
int mount_resctrlfs(void);
int umount_resctrlfs(void);
bool resctrl_resource_exists(const char *resource);
bool resctrl_mon_feature_exists(const char *resource, const char *feature);
bool resource_info_file_exists(const char *resource, const char *file);
bool test_resource_feature_check(const struct resctrl_test *test);
char *fgrep(FILE *inf, const char *str);
int taskset_benchmark(pid_t bm_pid, int cpu_no, cpu_set_t *old_affinity);
int taskset_restore(pid_t bm_pid, cpu_set_t *old_affinity);
int write_schemata(const char *ctrlgrp, char *schemata, int cpu_no,
                   const char *resource);
int write_bm_pid_to_resctrl(pid_t bm_pid, const char *ctrlgrp, const char *mongrp);
int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
                    int group_fd, unsigned long flags);
unsigned char *alloc_buffer(size_t buf_size, bool memflush);
void mem_flush(unsigned char *buf, size_t buf_size);
void fill_cache_read(unsigned char *buf, size_t buf_size, bool once);
ssize_t get_fill_buf_size(int cpu_no, const char *cache_type);
int initialize_read_mem_bw_imc(void);
int measure_read_mem_bw(const struct user_params *uparams,
                        struct resctrl_val_param *param, pid_t bm_pid);
void initialize_mem_bw_resctrl(const struct resctrl_val_param *param,
                               int domain_id);
int resctrl_val(const struct resctrl_test *test,
                const struct user_params *uparams,
                struct resctrl_val_param *param);
unsigned long create_bit_mask(unsigned int start, unsigned int len);
unsigned int count_contiguous_bits(unsigned long val, unsigned int *start);
int get_full_cbm(const char *cache_type, unsigned long *mask);
int get_mask_no_shareable(const char *cache_type, unsigned long *mask);
int get_cache_size(int cpu_no, const char *cache_type, unsigned long *cache_size);
int resource_info_unsigned_get(const char *resource, const char *filename, unsigned int *val);
void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
int signal_handler_register(const struct resctrl_test *test);
void signal_handler_unregister(void);
unsigned int count_bits(unsigned long n);
int snc_kernel_support(void);

void perf_event_attr_initialize(struct perf_event_attr *pea, __u64 config);
void perf_event_initialize_read_format(struct perf_event_read *pe_read);
int perf_open(struct perf_event_attr *pea, pid_t pid, int cpu_no);
int perf_event_reset_enable(int pe_fd);
int perf_event_measure(int pe_fd, struct perf_event_read *pe_read,
                       const char *filename, pid_t bm_pid);
int measure_llc_resctrl(const char *filename, pid_t bm_pid);
void show_cache_info(int no_of_bits, __u64 avg_llc_val, size_t cache_span, bool lines);

/*
 * cache_portion_size - Calculate the size of a cache portion
 * @cache_size:         Total cache size in bytes
 * @portion_mask:       Cache portion mask
 * @full_cache_mask:    Full Cache Bit Mask (CBM) for the cache
 *
 * Return: The size of the cache portion in bytes.
 */
static inline unsigned long cache_portion_size(unsigned long cache_size,
                                               unsigned long portion_mask,
                                               unsigned long full_cache_mask)
{
        unsigned int bits = count_bits(full_cache_mask);

        /*
         * With no bits the full CBM, assume cache cannot be split into
         * smaller portions. To avoid divide by zero, return cache_size.
         */
        if (!bits)
                return cache_size;

        return cache_size * count_bits(portion_mask) / bits;
}

extern struct resctrl_test mbm_test;
extern struct resctrl_test mba_test;
extern struct resctrl_test cmt_test;
extern struct resctrl_test l3_cat_test;
extern struct resctrl_test l3_noncont_cat_test;
extern struct resctrl_test l2_noncont_cat_test;

#endif /* RESCTRL_H */