// 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"

#define CON_MON_LCC_OCCUP_PATH          \
        "%s/%s/mon_groups/%s/mon_data/mon_L3_%02d/llc_occupancy"

#define CON_LCC_OCCUP_PATH              \
        "%s/%s/mon_data/mon_L3_%02d/llc_occupancy"

#define MON_LCC_OCCUP_PATH              \
        "%s/mon_groups/%s/mon_data/mon_L3_%02d/llc_occupancy"

#define LCC_OCCUP_PATH                  \
        "%s/mon_data/mon_L3_%02d/llc_occupancy"

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 char mbm_total_path[1024];
static int imcs;
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);
                }
        }
}

static int open_perf_event(int i, int cpu_no, int j)
{
        imc_counters_config[i][j].fd =
                perf_event_open(&imc_counters_config[i][j].pe, -1, cpu_no, -1,
                                PERF_FLAG_FD_CLOEXEC);

        if (imc_counters_config[i][j].fd == -1) {
                fprintf(stderr, "Error opening leader %llx\n",
                        imc_counters_config[i][j].pe.config);

                return -1;
        }

        return 0;
}

/* Get type and config (read and write) of an iMC counter */
static int read_from_imc_dir(char *imc_dir, int count)
{
        char cas_count_cfg[1024], imc_counter_cfg[1024], imc_counter_type[1024];
        FILE *fp;

        /* Get type of iMC counter */
        sprintf(imc_counter_type, "%s%s", imc_dir, "type");
        fp = fopen(imc_counter_type, "r");
        if (!fp) {
                perror("Failed to open imc counter type file");

                return -1;
        }
        if (fscanf(fp, "%u", &imc_counters_config[count][READ].type) <= 0) {
                perror("Could not get imc type");
                fclose(fp);

                return -1;
        }
        fclose(fp);

        imc_counters_config[count][WRITE].type =
                                imc_counters_config[count][READ].type;

        /* Get read config */
        sprintf(imc_counter_cfg, "%s%s", imc_dir, READ_FILE_NAME);
        fp = fopen(imc_counter_cfg, "r");
        if (!fp) {
                perror("Failed to open imc config file");

                return -1;
        }
        if (fscanf(fp, "%s", cas_count_cfg) <= 0) {
                perror("Could not get imc cas count read");
                fclose(fp);

                return -1;
        }
        fclose(fp);

        get_event_and_umask(cas_count_cfg, count, READ);

        /* Get write config */
        sprintf(imc_counter_cfg, "%s%s", imc_dir, WRITE_FILE_NAME);
        fp = fopen(imc_counter_cfg, "r");
        if (!fp) {
                perror("Failed to open imc config file");

                return -1;
        }
        if  (fscanf(fp, "%s", cas_count_cfg) <= 0) {
                perror("Could not get imc cas count write");
                fclose(fp);

                return -1;
        }
        fclose(fp);

        get_event_and_umask(cas_count_cfg, count, WRITE);

        return 0;
}

/*
 * A system can have 'n' number of iMC (Integrated Memory Controller)
 * counters, get that 'n'. For each iMC counter get it's type and config.
 * Also, each counter has two configs, one for read and the other for write.
 * A config again has two parts, event and umask.
 * Enumerate all these details into an array of structures.
 *
 * Return: >= 0 on success. < 0 on failure.
 */
static int num_of_imcs(void)
{
        unsigned int count = 0;
        char imc_dir[512];
        struct dirent *ep;
        int ret;
        DIR *dp;

        dp = opendir(DYN_PMU_PATH);
        if (dp) {
                while ((ep = readdir(dp))) {
                        if (strstr(ep->d_name, UNCORE_IMC)) {
                                sprintf(imc_dir, "%s/%s/", DYN_PMU_PATH,
                                        ep->d_name);
                                ret = read_from_imc_dir(imc_dir, count);
                                if (ret) {
                                        closedir(dp);

                                        return ret;
                                }
                                count++;
                        }
                }
                closedir(dp);
                if (count == 0) {
                        perror("Unable find iMC counters!\n");

                        return -1;
                }
        } else {
                perror("Unable to open PMU directory!\n");

                return -1;
        }

        return count;
}

static int initialize_mem_bw_imc(void)
{
        int imc, j;

        imcs = num_of_imcs();
        if (imcs <= 0)
                return imcs;

        /* Initialize perf_event_attr structures for all iMC's */
        for (imc = 0; imc < imcs; imc++) {
                for (j = 0; j < 2; j++)
                        membw_initialize_perf_event_attr(imc, j);
        }

        return 0;
}

/*
 * get_mem_bw_imc:      Memory band width as reported by iMC counters
 * @cpu_no:             CPU number that the benchmark PID is binded to
 * @bw_report:          Bandwidth report type (reads, writes)
 *
 * Memory B/W utilized by a process on a socket can be calculated using
 * iMC counters. Perf events are used to read these counters.
 *
 * Return: >= 0 on success. < 0 on failure.
 */
static float get_mem_bw_imc(int cpu_no, char *bw_report)
{
        float reads, writes, of_mul_read, of_mul_write;
        int imc, j, ret;

        /* Start all iMC counters to log values (both read and write) */
        reads = 0, writes = 0, of_mul_read = 1, of_mul_write = 1;
        for (imc = 0; imc < imcs; imc++) {
                for (j = 0; j < 2; j++) {
                        ret = open_perf_event(imc, cpu_no, j);
                        if (ret)
                                return -1;
                }
                for (j = 0; j < 2; j++)
                        membw_ioctl_perf_event_ioc_reset_enable(imc, j);
        }

        sleep(1);

        /* Stop counters after a second to get results (both read and write) */
        for (imc = 0; imc < imcs; imc++) {
                for (j = 0; j < 2; j++)
                        membw_ioctl_perf_event_ioc_disable(imc, j);
        }

        /*
         * Get results which are stored in struct type imc_counter_config
         * Take over flow into consideration before calculating total b/w
         */
        for (imc = 0; imc < imcs; imc++) {
                struct imc_counter_config *r =
                        &imc_counters_config[imc][READ];
                struct imc_counter_config *w =
                        &imc_counters_config[imc][WRITE];

                if (read(r->fd, &r->return_value,
                         sizeof(struct membw_read_format)) == -1) {
                        perror("Couldn't get read b/w through iMC");

                        return -1;
                }

                if (read(w->fd, &w->return_value,
                         sizeof(struct membw_read_format)) == -1) {
                        perror("Couldn't get write bw through iMC");

                        return -1;
                }

                __u64 r_time_enabled = r->return_value.time_enabled;
                __u64 r_time_running = r->return_value.time_running;

                if (r_time_enabled != r_time_running)
                        of_mul_read = (float)r_time_enabled /
                                        (float)r_time_running;

                __u64 w_time_enabled = w->return_value.time_enabled;
                __u64 w_time_running = w->return_value.time_running;

                if (w_time_enabled != w_time_running)
                        of_mul_write = (float)w_time_enabled /
                                        (float)w_time_running;
                reads += r->return_value.value * of_mul_read * SCALE;
                writes += w->return_value.value * of_mul_write * SCALE;
        }

        for (imc = 0; imc < imcs; imc++) {
                close(imc_counters_config[imc][READ].fd);
                close(imc_counters_config[imc][WRITE].fd);
        }

        if (strcmp(bw_report, "reads") == 0)
                return reads;

        if (strcmp(bw_report, "writes") == 0)
                return writes;

        return (reads + writes);
}

void set_mbm_path(const char *ctrlgrp, const char *mongrp, int resource_id)
{
        if (ctrlgrp && mongrp)
                sprintf(mbm_total_path, CON_MON_MBM_LOCAL_BYTES_PATH,
                        RESCTRL_PATH, ctrlgrp, mongrp, resource_id);
        else if (!ctrlgrp && mongrp)
                sprintf(mbm_total_path, MON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH,
                        mongrp, resource_id);
        else if (ctrlgrp && !mongrp)
                sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH, RESCTRL_PATH,
                        ctrlgrp, resource_id);
        else if (!ctrlgrp && !mongrp)
                sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH, RESCTRL_PATH,
                        resource_id);
}

/*
 * initialize_mem_bw_resctrl:   Appropriately populate "mbm_total_path"
 * @ctrlgrp:                    Name of the control monitor group (con_mon grp)
 * @mongrp:                     Name of the monitor group (mon grp)
 * @cpu_no:                     CPU number that the benchmark PID is binded to
 * @resctrl_val:                Resctrl feature (Eg: mbm, mba.. etc)
 */
static void initialize_mem_bw_resctrl(const char *ctrlgrp, const char *mongrp,
                                      int cpu_no, char *resctrl_val)
{
        int resource_id;

        if (get_resource_id(cpu_no, &resource_id) < 0) {
                perror("Could not get resource_id");
                return;
        }

        if (strcmp(resctrl_val, "mbm") == 0)
                set_mbm_path(ctrlgrp, mongrp, resource_id);

        if ((strcmp(resctrl_val, "mba") == 0)) {
                if (ctrlgrp)
                        sprintf(mbm_total_path, CON_MBM_LOCAL_BYTES_PATH,
                                RESCTRL_PATH, ctrlgrp, resource_id);
                else
                        sprintf(mbm_total_path, MBM_LOCAL_BYTES_PATH,
                                RESCTRL_PATH, resource_id);
        }
}

/*
 * Get MBM Local bytes as reported by resctrl FS
 * For MBM,
 * 1. If con_mon grp and mon grp are given, then read from con_mon grp's mon grp
 * 2. If only con_mon grp is given, then read from con_mon grp
 * 3. If both are not given, then read from root con_mon grp
 * For MBA,
 * 1. If con_mon grp is given, then read from it
 * 2. If con_mon grp is not given, then read from root con_mon grp
 */
static unsigned long get_mem_bw_resctrl(void)
{
        unsigned long mbm_total = 0;
        FILE *fp;

        fp = fopen(mbm_total_path, "r");
        if (!fp) {
                perror("Failed to open total bw file");

                return -1;
        }
        if (fscanf(fp, "%lu", &mbm_total) <= 0) {
                perror("Could not get mbm local bytes");
                fclose(fp);

                return -1;
        }
        fclose(fp);

        return mbm_total;
}

pid_t bm_pid, ppid;

void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
{
        kill(bm_pid, SIGKILL);
        umount_resctrlfs();
        tests_cleanup();
        printf("Ending\n\n");

        exit(EXIT_SUCCESS);
}

/*
 * print_results_bw:    the memory bandwidth results are stored in a file
 * @filename:           file that stores the results
 * @bm_pid:             child pid that runs benchmark
 * @bw_imc:             perf imc counter value
 * @bw_resc:            memory bandwidth value
 *
 * Return:              0 on success. non-zero on failure.
 */
static int print_results_bw(char *filename,  int bm_pid, float bw_imc,
                            unsigned long bw_resc)
{
        unsigned long diff = fabs(bw_imc - bw_resc);
        FILE *fp;

        if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
                printf("Pid: %d \t Mem_BW_iMC: %f \t ", bm_pid, bw_imc);
                printf("Mem_BW_resc: %lu \t Difference: %lu\n", bw_resc, diff);
        } else {
                fp = fopen(filename, "a");
                if (!fp) {
                        perror("Cannot open results file");

                        return errno;
                }
                if (fprintf(fp, "Pid: %d \t Mem_BW_iMC: %f \t Mem_BW_resc: %lu \t Difference: %lu\n",
                            bm_pid, bw_imc, bw_resc, diff) <= 0) {
                        fclose(fp);
                        perror("Could not log results.");

                        return errno;
                }
                fclose(fp);
        }

        return 0;
}

static void set_cqm_path(const char *ctrlgrp, const char *mongrp, char sock_num)
{
        if (strlen(ctrlgrp) && strlen(mongrp))
                sprintf(llc_occup_path, CON_MON_LCC_OCCUP_PATH, RESCTRL_PATH,
                        ctrlgrp, mongrp, sock_num);
        else if (!strlen(ctrlgrp) && strlen(mongrp))
                sprintf(llc_occup_path, MON_LCC_OCCUP_PATH, RESCTRL_PATH,
                        mongrp, sock_num);
        else if (strlen(ctrlgrp) && !strlen(mongrp))
                sprintf(llc_occup_path, CON_LCC_OCCUP_PATH, RESCTRL_PATH,
                        ctrlgrp, sock_num);
        else if (!strlen(ctrlgrp) && !strlen(mongrp))
                sprintf(llc_occup_path, LCC_OCCUP_PATH, RESCTRL_PATH, sock_num);
}

/*
 * initialize_llc_occu_resctrl: Appropriately populate "llc_occup_path"
 * @ctrlgrp:                    Name of the control monitor group (con_mon grp)
 * @mongrp:                     Name of the monitor group (mon grp)
 * @cpu_no:                     CPU number that the benchmark PID is binded to
 * @resctrl_val:                Resctrl feature (Eg: cat, cqm.. etc)
 */
static void initialize_llc_occu_resctrl(const char *ctrlgrp, const char *mongrp,
                                        int cpu_no, char *resctrl_val)
{
        int resource_id;

        if (get_resource_id(cpu_no, &resource_id) < 0) {
                perror("# Unable to resource_id");
                return;
        }

        if (strcmp(resctrl_val, "cqm") == 0)
                set_cqm_path(ctrlgrp, mongrp, resource_id);
}

static int
measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start)
{
        unsigned long bw_imc, bw_resc, bw_resc_end;
        int ret;

        /*
         * Measure memory bandwidth from resctrl and from
         * another source which is perf imc value or could
         * be something else if perf imc event is not available.
         * Compare the two values to validate resctrl value.
         * It takes 1sec to measure the data.
         */
        bw_imc = get_mem_bw_imc(param->cpu_no, param->bw_report);
        if (bw_imc <= 0)
                return bw_imc;

        bw_resc_end = get_mem_bw_resctrl();
        if (bw_resc_end <= 0)
                return bw_resc_end;

        bw_resc = (bw_resc_end - *bw_resc_start) / MB;
        ret = print_results_bw(param->filename, bm_pid, bw_imc, bw_resc);
        if (ret)
                return ret;

        *bw_resc_start = bw_resc_end;

        return 0;
}

/*
 * resctrl_val: execute benchmark and measure memory bandwidth on
 *                      the benchmark
 * @benchmark_cmd:      benchmark command and its arguments
 * @param:              parameters passed to resctrl_val()
 *
 * Return:              0 on success. non-zero on failure.
 */
int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
{
        char *resctrl_val = param->resctrl_val;
        unsigned long bw_resc_start = 0;
        struct sigaction sigact;
        int ret = 0, pipefd[2];
        char pipe_message = 0;
        union sigval value;

        if (strcmp(param->filename, "") == 0)
                sprintf(param->filename, "stdio");

        if ((strcmp(resctrl_val, "mba")) == 0 ||
            (strcmp(resctrl_val, "mbm")) == 0) {
                ret = validate_bw_report_request(param->bw_report);
                if (ret)
                        return ret;
        }

        ret = remount_resctrlfs(param->mum_resctrlfs);
        if (ret)
                return ret;

        /*
         * If benchmark wasn't successfully started by child, then child should
         * kill parent, so save parent's pid
         */
        ppid = getpid();

        if (pipe(pipefd)) {
                perror("# Unable to create pipe");

                return -1;
        }

        /*
         * Fork to start benchmark, save child's pid so that it can be killed
         * when needed
         */
        bm_pid = fork();
        if (bm_pid == -1) {
                perror("# Unable to fork");

                return -1;
        }

        if (bm_pid == 0) {
                /*
                 * Mask all signals except SIGUSR1, parent uses SIGUSR1 to
                 * start benchmark
                 */
                sigfillset(&sigact.sa_mask);
                sigdelset(&sigact.sa_mask, SIGUSR1);

                sigact.sa_sigaction = run_benchmark;
                sigact.sa_flags = SA_SIGINFO;

                /* Register for "SIGUSR1" signal from parent */
                if (sigaction(SIGUSR1, &sigact, NULL))
                        PARENT_EXIT("Can't register child for signal");

                /* Tell parent that child is ready */
                close(pipefd[0]);
                pipe_message = 1;
                if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
                    sizeof(pipe_message)) {
                        perror("# failed signaling parent process");
                        close(pipefd[1]);
                        return -1;
                }
                close(pipefd[1]);

                /* Suspend child until delivery of "SIGUSR1" from parent */
                sigsuspend(&sigact.sa_mask);

                PARENT_EXIT("Child is done");
        }

        printf("# benchmark PID: %d\n", bm_pid);

        /*
         * Register CTRL-C handler for parent, as it has to kill benchmark
         * before exiting
         */
        sigact.sa_sigaction = ctrlc_handler;
        sigemptyset(&sigact.sa_mask);
        sigact.sa_flags = SA_SIGINFO;
        if (sigaction(SIGINT, &sigact, NULL) ||
            sigaction(SIGHUP, &sigact, NULL)) {
                perror("# sigaction");
                ret = errno;
                goto out;
        }

        value.sival_ptr = benchmark_cmd;

        /* Taskset benchmark to specified cpu */
        ret = taskset_benchmark(bm_pid, param->cpu_no);
        if (ret)
                goto out;

        /* Write benchmark to specified control&monitoring grp in resctrl FS */
        ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp,
                                      resctrl_val);
        if (ret)
                goto out;

        if ((strcmp(resctrl_val, "mbm") == 0) ||
            (strcmp(resctrl_val, "mba") == 0)) {
                ret = initialize_mem_bw_imc();
                if (ret)
                        goto out;

                initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp,
                                          param->cpu_no, resctrl_val);
        } else if (strcmp(resctrl_val, "cqm") == 0)
                initialize_llc_occu_resctrl(param->ctrlgrp, param->mongrp,
                                            param->cpu_no, resctrl_val);

        /* Parent waits for child to be ready. */
        close(pipefd[1]);
        while (pipe_message != 1) {
                if (read(pipefd[0], &pipe_message, sizeof(pipe_message)) <
                    sizeof(pipe_message)) {
                        perror("# failed reading message from child process");
                        close(pipefd[0]);
                        goto out;
                }
        }
        close(pipefd[0]);

        /* Signal child to start benchmark */
        if (sigqueue(bm_pid, SIGUSR1, value) == -1) {
                perror("# sigqueue SIGUSR1 to child");
                ret = errno;
                goto out;
        }

        /* Give benchmark enough time to fully run */
        sleep(1);

        /* Test runs until the callback setup() tells the test to stop. */
        while (1) {
                if ((strcmp(resctrl_val, "mbm") == 0) ||
                    (strcmp(resctrl_val, "mba") == 0)) {
                        ret = param->setup(1, param);
                        if (ret) {
                                ret = 0;
                                break;
                        }

                        ret = measure_vals(param, &bw_resc_start);
                        if (ret)
                                break;
                } else if (strcmp(resctrl_val, "cqm") == 0) {
                        ret = param->setup(1, param);
                        if (ret) {
                                ret = 0;
                                break;
                        }
                        sleep(1);
                        ret = measure_cache_vals(param, bm_pid);
                        if (ret)
                                break;
                } else {
                        break;
                }
        }

out:
        kill(bm_pid, SIGKILL);
        umount_resctrlfs();

        return ret;
}