/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2019 Joyent, Inc.
 * Copyright 2022 Oxide Computer Company
 */

/*
 * Private command to manipulate link speeds of PCIe bridges and allow
 * retraining. This is designed to aid debugging.
 */

#include <unistd.h>
#include <stdarg.h>
#include <stdio.h>
#include <libgen.h>
#include <string.h>
#include <err.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <pcieb_ioctl.h>

static const char *pcieb_progname;

static void
pcieb_usage(const char *fmt, ...)
{
        if (fmt != NULL) {
                va_list ap;

                (void) fprintf(stderr, "%s: ", pcieb_progname);
                va_start(ap, fmt);
                (void) vfprintf(stderr, fmt, ap);
                va_end(ap);
        }

        (void) fprintf(stderr, "Usage: %s [-x] [-s speed] pcie-bridge\n"
            "\n"
            "\t-s speed         Set link to speed\n",
            "\t-x               Retrain link\n",
            pcieb_progname);

}

static uint32_t
pcieb_parse_speed(const char *s)
{
        if (strcasecmp(s, "2.5") == 0 || strcasecmp(s, "gen1") == 0) {
                return (PCIEB_LINK_SPEED_GEN1);
        } else if (strcasecmp(s, "5") == 0 || strcasecmp(s, "gen2") == 0) {
                return (PCIEB_LINK_SPEED_GEN2);
        } else if (strcasecmp(s, "8") == 0 || strcasecmp(s, "gen3") == 0) {
                return (PCIEB_LINK_SPEED_GEN3);
        } else if (strcasecmp(s, "16") == 0 || strcasecmp(s, "gen4") == 0) {
                return (PCIEB_LINK_SPEED_GEN4);
        } else if (strcasecmp(s, "32") == 0 || strcasecmp(s, "gen5") == 0) {
                return (PCIEB_LINK_SPEED_GEN5);
        } else if (strcasecmp(s, "64") == 0 || strcasecmp(s, "gen6") == 0) {
                return (PCIEB_LINK_SPEED_GEN6);
        } else {
                errx(EXIT_FAILURE, "invalid speed: %s", s);
        }
}

int
main(int argc, char *argv[])
{
        int c;
        boolean_t retrain = B_FALSE;
        boolean_t set = B_FALSE;
        boolean_t get = B_TRUE;
        uint32_t speed = PCIEB_LINK_SPEED_UNKNOWN;
        int fd;

        pcieb_progname = basename(argv[0]);

        while ((c = getopt(argc, argv, ":xs:")) != -1) {
                switch (c) {
                case 's':
                        speed = pcieb_parse_speed(optarg);
                        set = B_TRUE;
                        get = B_FALSE;
                        break;
                case 'x':
                        retrain = B_TRUE;
                        get = B_FALSE;
                        break;
                case ':':
                        pcieb_usage("option -%c requires an operand\n", optopt);
                        return (2);
                case '?':
                default:
                        pcieb_usage("unknown option: -%c\n", optopt);
                        return (2);

                }
        }

        argc -= optind;
        argv += optind;

        if (argc != 1) {
                pcieb_usage("missing required PCIe bridge device\n");
                return (2);
        }

        if ((fd = open(argv[0], O_RDWR)) < 0) {
                err(EXIT_FAILURE, "failed to open %s", argv[0]);
        }

        if (set) {
                pcieb_ioctl_target_speed_t pits;

                pits.pits_flags = 0;
                pits.pits_speed = speed;

                if (ioctl(fd, PCIEB_IOCTL_SET_TARGET_SPEED, &pits) != 0) {
                        err(EXIT_FAILURE, "failed to set target speed");
                }
        }

        if (retrain) {
                if (ioctl(fd, PCIEB_IOCTL_RETRAIN) != 0) {
                        err(EXIT_FAILURE, "failed to retrain link");
                }
        }

        if (get) {
                pcieb_ioctl_target_speed_t pits;

                if (ioctl(fd, PCIEB_IOCTL_GET_TARGET_SPEED, &pits) != 0) {
                        err(EXIT_FAILURE, "failed to get target speed");
                }

                (void) printf("Bridge target speed: ");
                switch (pits.pits_speed) {
                case PCIEB_LINK_SPEED_GEN1:
                        (void) printf("2.5 GT/s (gen1)\n");
                        break;
                case PCIEB_LINK_SPEED_GEN2:
                        (void) printf("5.0 GT/s (gen2)\n");
                        break;
                case PCIEB_LINK_SPEED_GEN3:
                        (void) printf("8.0 GT/s (gen3)\n");
                        break;
                case PCIEB_LINK_SPEED_GEN4:
                        (void) printf("16.0 GT/s (gen4)\n");
                        break;
                case PCIEB_LINK_SPEED_GEN5:
                        (void) printf("32.0 GT/s (gen5)\n");
                        break;
                case PCIEB_LINK_SPEED_GEN6:
                        (void) printf("64.0 GT/s (gen6)\n");
                        break;
                default:
                        (void) printf("Unknown Value: 0x%x\n", pits.pits_speed);
                }

                if ((pits.pits_flags & ~PCIEB_FLAGS_ADMIN_SET) != 0) {
                        (void) printf("Unknown flags: 0x%x\n", pits.pits_flags);
                } else if ((pits.pits_flags & PCIEB_FLAGS_ADMIN_SET) != 0) {
                        (void) printf("Flags: Admin Set Speed\n");
                }
        }

        (void) close(fd);
        return (0);
}