/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2003,2004 Joseph Koshy
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include <sys/param.h>
#include <sys/queue.h>
#include <sys/cpuset.h>
#include <sys/sysctl.h>

#include <assert.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pmc.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

/* Compile time defaults */

#define PMCC_PRINT_USAGE        0
#define PMCC_PRINT_EVENTS       1
#define PMCC_LIST_STATE         2
#define PMCC_ENABLE_DISABLE     3
#define PMCC_SHOW_STATISTICS    4

#define PMCC_CPU_ALL            -1
#define PMCC_CPU_WILDCARD       '*'

#define PMCC_PMC_ALL            -1
#define PMCC_PMC_WILDCARD       '*'

#define PMCC_OP_IGNORE          0
#define PMCC_OP_DISABLE         1
#define PMCC_OP_ENABLE          2

#define PMCC_PROGRAM_NAME       "pmccontrol"

static STAILQ_HEAD(pmcc_op_list, pmcc_op) head = STAILQ_HEAD_INITIALIZER(head);

struct pmcc_op {
        char    op_cpu;
        char    op_pmc;
        char    op_op;
        STAILQ_ENTRY(pmcc_op) op_next;
};

/* Function Prototypes */
#if     DEBUG
static void     pmcc_init_debug(void);
#endif

static int      pmcc_do_list_state(void);
static int      pmcc_do_enable_disable(struct pmcc_op_list *);
static int      pmcc_do_list_events(void);

/* Globals */

static char usage_message[] =
        "Usage:\n"
        "       " PMCC_PROGRAM_NAME " -L\n"
        "       " PMCC_PROGRAM_NAME " -l\n"
        "       " PMCC_PROGRAM_NAME " -s\n"
        "       " PMCC_PROGRAM_NAME " [-e pmc | -d pmc | -c cpu] ...";

#if DEBUG
static FILE *debug_stream = NULL;
#endif

#if DEBUG
#define DEBUG_MSG(...)                                                  \
        (void) fprintf(debug_stream, "[pmccontrol] " __VA_ARGS__)
#else
#define DEBUG_MSG(m)            /*  */
#endif /* !DEBUG */

#if DEBUG
/* log debug messages to a separate file */
static void
pmcc_init_debug(void)
{
        char *fn;

        fn = getenv("PMCCONTROL_DEBUG");
        if (fn != NULL)
        {
                debug_stream = fopen(fn, "w");
                if (debug_stream == NULL)
                        debug_stream = stderr;
        } else
                debug_stream = stderr;
}
#endif

static int
pmcc_do_enable_disable(struct pmcc_op_list *op_list)
{
        int c, error, i, j, ncpu, npmc, t;
        struct pmcc_op *np;
        unsigned char *map;
        unsigned char op;
        int cpu, pmc;

        if ((ncpu = pmc_ncpu()) < 0)
                err(EX_OSERR, "Unable to determine the number of cpus");

        /* Determine the maximum number of PMCs in any CPU. */
        npmc = 0;
        for (c = 0; c < ncpu; c++) {
                if ((t = pmc_npmc(c)) < 0)
                        err(EX_OSERR,
                            "Unable to determine the number of PMCs in CPU %d",
                            c);
                npmc = MAX(t, npmc);
        }

        if (npmc == 0)
                errx(EX_CONFIG, "No PMCs found");

        if ((map = calloc(npmc, ncpu)) == NULL)
                err(EX_SOFTWARE, "Out of memory");

        error = 0;
        STAILQ_FOREACH(np, op_list, op_next) {

                cpu = np->op_cpu;
                pmc = np->op_pmc;
                op  = np->op_op;

                if (cpu >= ncpu)
                        errx(EX_DATAERR, "CPU id too large: \"%d\"", cpu);

                if (pmc >= npmc)
                        errx(EX_DATAERR, "PMC id too large: \"%d\"", pmc);

#define MARKMAP(M,C,P,V)        do {                            \
                *((M) + (C)*npmc + (P)) = (V);                  \
} while (0)

#define SET_PMCS(C,P,V)         do {                            \
                if ((P) == PMCC_PMC_ALL) {                      \
                        for (j = 0; j < npmc; j++)              \
                                MARKMAP(map, (C), j, (V));      \
                } else                                          \
                        MARKMAP(map, (C), (P), (V));            \
} while (0)

#define MAP(M,C,P)      (*((M) + (C)*npmc + (P)))

                if (cpu == PMCC_CPU_ALL)
                        for (i = 0; i < ncpu; i++) {
                                SET_PMCS(i, pmc, op);
                        }
                else
                        SET_PMCS(cpu, pmc, op);
        }

        /* Configure PMCS */
        for (i = 0; i < ncpu; i++)
                for (j = 0; j < npmc; j++) {
                        unsigned char b;

                        b = MAP(map, i, j);

                        error = 0;

                        if (b == PMCC_OP_ENABLE)
                                error = pmc_enable(i, j);
                        else if (b == PMCC_OP_DISABLE)
                                error = pmc_disable(i, j);

                        if (error < 0)
                                err(EX_OSERR, "%s of PMC %d on CPU %d failed",
                                    b == PMCC_OP_ENABLE ? "Enable" : "Disable",
                                    j, i);
                }

        return error;
}

static int
pmcc_do_list_state(void)
{
        cpuset_t logical_cpus_mask;
        long cpusetsize;
        size_t setsize;
        int c, cpu, n, npmc, ncpu;
        struct pmc_info *pd;
        struct pmc_pmcinfo *pi;
        const struct pmc_cpuinfo *pc;

        if (pmc_cpuinfo(&pc) != 0)
                err(EX_OSERR, "Unable to determine CPU information");

        printf("%d %s CPUs present, with %d PMCs per CPU\n", pc->pm_ncpu, 
               pmc_name_of_cputype(pc->pm_cputype),
                pc->pm_npmc);

        /* Determine the set of logical CPUs. */
        cpusetsize = sysconf(_SC_CPUSET_SIZE);
        if (cpusetsize == -1 || (u_long)cpusetsize > sizeof(cpuset_t))
                err(EX_OSERR, "Cannot determine which CPUs are logical");
        CPU_ZERO(&logical_cpus_mask);
        setsize = (size_t)cpusetsize;
        if (sysctlbyname("machdep.logical_cpus_mask", &logical_cpus_mask,
            &setsize, NULL, 0) < 0)
                CPU_ZERO(&logical_cpus_mask);

        ncpu = pc->pm_ncpu;

        for (c = cpu = 0; cpu < ncpu; cpu++) {
                if (pmc_pmcinfo(cpu, &pi) < 0) {
                        if (errno == ENXIO)
                                continue;
                        err(EX_OSERR, "Unable to get PMC status for CPU %d",
                            cpu);
                }

                printf("#CPU %d:\n", c++);
                npmc = pmc_npmc(cpu);
                printf("#N  NAME             CLASS  STATE    ROW-DISP\n");

                for (n = 0; n < npmc; n++) {
                        pd = &pi->pm_pmcs[n];

                        printf(" %-2d %-16s %-6s %-8s %-10s",
                            n,
                            pd->pm_name,
                            pmc_name_of_class(pd->pm_class),
                            pd->pm_enabled ? "ENABLED" : "DISABLED",
                            pmc_name_of_disposition(pd->pm_rowdisp));

                        if (pd->pm_ownerpid != -1) {
                                printf(" (pid %d)", pd->pm_ownerpid);
                                printf(" %-32s",
                                    pmc_name_of_event(pd->pm_event));
                                if (PMC_IS_SAMPLING_MODE(pd->pm_mode))
                                        printf(" (reload count %jd)",
                                            pd->pm_reloadcount);
                        }
                        printf("\n");
                }
                free(pi);
        }
        return 0;
}

static int
pmcc_do_list_events(void)
{
        enum pmc_class c;
        unsigned int i, j, nevents;
        const char **eventnamelist;
        const struct pmc_cpuinfo *ci;

        /* First, try pmu events. */
        if (pmc_pmu_enabled()) {
                pmc_pmu_print_counters(NULL);
                return (0);
        }

        /* Otherwise, use the legacy pmc(3) interfaces. */
        if (pmc_cpuinfo(&ci) != 0)
                err(EX_OSERR, "Unable to determine CPU information");

        eventnamelist = NULL;

        for (i = 0; i < ci->pm_nclass; i++) {
                c = ci->pm_classes[i].pm_class;

                printf("%s\n", pmc_name_of_class(c));
                if (pmc_event_names_of_class(c, &eventnamelist, &nevents) < 0)
                        err(EX_OSERR,
"ERROR: Cannot find information for event class \"%s\"",
                            pmc_name_of_class(c));

                for (j = 0; j < nevents; j++)
                        printf("\t%s\n", eventnamelist[j]);

                free(eventnamelist);
        }
        return 0;
}

static int
pmcc_show_statistics(void)
{

        struct pmc_driverstats gms;

        if (pmc_get_driver_stats(&gms) < 0)
                err(EX_OSERR, "ERROR: cannot retrieve driver statistics");

        /*
         * Print statistics.
         */

#define PRINT(N,V)      (void) printf("%-40s %d\n", (N), gms.pm_##V)
        PRINT("interrupts processed:", intr_processed);
        PRINT("non-PMC interrupts:", intr_ignored);
        PRINT("sampling stalls due to space shortages:", intr_bufferfull);
        PRINT("system calls:", syscalls);
        PRINT("system calls with errors:", syscall_errors);
        PRINT("buffer requests:", buffer_requests);
        PRINT("buffer requests failed:", buffer_requests_failed);
        PRINT("sampling log sweeps:", log_sweeps);

        return 0;
}

/*
 * Main
 */

int
main(int argc, char **argv)
{
        int error, command, currentcpu, option, pmc;
        char *dummy;
        struct pmcc_op *p;

#if DEBUG
        pmcc_init_debug();
#endif

        /* parse args */

        currentcpu = PMCC_CPU_ALL;
        command    = PMCC_PRINT_USAGE;
        error      = 0;

        STAILQ_INIT(&head);

        while ((option = getopt(argc, argv, ":c:d:e:lLs")) != -1)
                switch (option) {
                case 'L':
                        if (command != PMCC_PRINT_USAGE) {
                                error = 1;
                                break;
                        }
                        command = PMCC_PRINT_EVENTS;
                        break;

                case 'c':
                        if (command != PMCC_PRINT_USAGE &&
                            command != PMCC_ENABLE_DISABLE) {
                                error = 1;
                                break;
                        }
                        command = PMCC_ENABLE_DISABLE;

                        if (*optarg == PMCC_CPU_WILDCARD)
                                currentcpu = PMCC_CPU_ALL;
                        else {
                                currentcpu = strtoul(optarg, &dummy, 0);
                                if (*dummy != '\0' || currentcpu < 0)
                                        errx(EX_DATAERR,
                                            "\"%s\" is not a valid CPU id",
                                            optarg);
                        }
                        break;

                case 'd':
                case 'e':
                        if (command != PMCC_PRINT_USAGE &&
                            command != PMCC_ENABLE_DISABLE) {
                                error = 1;
                                break;
                        }
                        command = PMCC_ENABLE_DISABLE;

                        if (*optarg == PMCC_PMC_WILDCARD)
                                pmc = PMCC_PMC_ALL;
                        else {
                                pmc = strtoul(optarg, &dummy, 0);
                                if (*dummy != '\0' || pmc < 0)
                                        errx(EX_DATAERR,
                                            "\"%s\" is not a valid PMC id",
                                            optarg);
                        }

                        if ((p = malloc(sizeof(*p))) == NULL)
                                err(EX_SOFTWARE, "Out of memory");

                        p->op_cpu = currentcpu;
                        p->op_pmc = pmc;
                        p->op_op  = option == 'd' ? PMCC_OP_DISABLE :
                            PMCC_OP_ENABLE;

                        STAILQ_INSERT_TAIL(&head, p, op_next);
                        break;

                case 'l':
                        if (command != PMCC_PRINT_USAGE) {
                                error = 1;
                                break;
                        }
                        command = PMCC_LIST_STATE;
                        break;

                case 's':
                        if (command != PMCC_PRINT_USAGE) {
                                error = 1;
                                break;
                        }
                        command = PMCC_SHOW_STATISTICS;
                        break;

                case ':':
                        errx(EX_USAGE,
                            "Missing argument to option '-%c'", optopt);
                        break;

                case '?':
                        warnx("Unrecognized option \"-%c\"", optopt);
                        errx(EX_USAGE, "%s", usage_message);
                        break;

                default:
                        error = 1;
                        break;

                }

        if (command == PMCC_PRINT_USAGE)
                (void) errx(EX_USAGE, "%s", usage_message);

        if (error)
                exit(EX_USAGE);

        if (pmc_init() < 0)
                err(EX_UNAVAILABLE,
                    "Initialization of the pmc(3) library failed");

        switch (command) {
        case PMCC_LIST_STATE:
                error = pmcc_do_list_state();
                break;
        case PMCC_PRINT_EVENTS:
                error = pmcc_do_list_events();
                break;
        case PMCC_SHOW_STATISTICS:
                error = pmcc_show_statistics();
                break;
        case PMCC_ENABLE_DISABLE:
                if (STAILQ_EMPTY(&head))
                        errx(EX_USAGE,
                            "No PMCs specified to enable or disable");
                error = pmcc_do_enable_disable(&head);
                break;
        default:
                assert(0);

        }

        if (error != 0)
                err(EX_OSERR, "Command failed");
        exit(0);
}