/*
 * S390 Channel I/O
 *
 * Copyright (c) 2013 Alexander Graf <agraf@suse.de>
 * Copyright (c) 2019 IBM Corp.
 *
 * Author(s): Jason J. Herne <jjherne@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or (at
 * your option) any later version. See the COPYING file in the top-level
 * directory.
 */

#include <string.h>
#include <stdio.h>
#include "s390-ccw.h"
#include "s390-arch.h"
#include "helper.h"
#include "cio.h"

static char chsc_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));

static int __do_cio(SubChannelId schid, uint32_t ccw_addr, int fmt, Irb *irb);

int enable_mss_facility(void)
{
    int ret;
    ChscAreaSda *sda_area = (ChscAreaSda *) chsc_page;

    memset(sda_area, 0, PAGE_SIZE);
    sda_area->request.length = 0x0400;
    sda_area->request.code = 0x0031;
    sda_area->operation_code = 0x2;

    ret = chsc(sda_area);
    if ((ret == 0) && (sda_area->response.code == 0x0001)) {
        return 0;
    }
    return -EIO;
}

void enable_subchannel(SubChannelId schid)
{
    Schib schib;

    stsch_err(schid, &schib);
    schib.pmcw.ena = 1;
    msch(schid, &schib);
}

uint16_t cu_type(SubChannelId schid)
{
    SenseId sense_data;
    Ccw1 sense_id_ccw = {
        .cmd_code = CCW_CMD_SENSE_ID,
        .flags = CCW_FLAG_SLI,
        .count = sizeof(sense_data),
        .cda = ptr2u32(&sense_data),
    };

    if (do_cio(schid, CU_TYPE_UNKNOWN, ptr2u32(&sense_id_ccw), CCW_FMT1)) {
        panic("Failed to run SenseID CCw\n");
    }

    return sense_data.cu_type;
}

int basic_sense(SubChannelId schid, uint16_t cutype, void *sense_data,
                 uint16_t data_size)
{
    Ccw1 senseCcw = {
        .cmd_code = CCW_CMD_BASIC_SENSE,
        .count = data_size,
        .cda = ptr2u32(sense_data),
    };
    Irb irb;

    return __do_cio(schid, ptr2u32(&senseCcw), CCW_FMT1, &irb);
}

static bool irb_error(Irb *irb)
{
    if (irb->scsw.cstat) {
        return true;
    }
    return irb->scsw.dstat != (SCSW_DSTAT_DEVEND | SCSW_DSTAT_CHEND);
}

static void print_eckd_dasd_sense_data(SenseDataEckdDasd *sd)
{
    char msgline[512];

    if (sd->config_info & 0x8000) {
        puts("Eckd Dasd Sense Data (fmt 24-bytes):");
    } else {
        puts("Eckd Dasd Sense Data (fmt 32-bytes):");
    }

    strcat(msgline, "    Sense Condition Flags :");
    if (sd->common_status & SNS_STAT0_CMD_REJECT) {
        strcat(msgline, " [Cmd-Reject]");
    }
    if (sd->common_status & SNS_STAT0_INTERVENTION_REQ) {
        strcat(msgline, " [Intervention-Required]");
    }
    if (sd->common_status & SNS_STAT0_BUS_OUT_CHECK) {
        strcat(msgline, " [Bus-Out-Parity-Check]");
    }
    if (sd->common_status & SNS_STAT0_EQUIPMENT_CHECK) {
        strcat(msgline, " [Equipment-Check]");
    }
    if (sd->common_status & SNS_STAT0_DATA_CHECK) {
        strcat(msgline, " [Data-Check]");
    }
    if (sd->common_status & SNS_STAT0_OVERRUN) {
        strcat(msgline, " [Overrun]");
    }
    if (sd->common_status & SNS_STAT0_INCOMPL_DOMAIN) {
        strcat(msgline, " [Incomplete-Domain]");
    }

    if (sd->status[0] & SNS_STAT1_PERM_ERR) {
        strcat(msgline, " [Permanent-Error]");
    }
    if (sd->status[0] & SNS_STAT1_INV_TRACK_FORMAT) {
        strcat(msgline, " [Invalid-Track-Fmt]");
    }
    if (sd->status[0] & SNS_STAT1_EOC) {
        strcat(msgline, " [End-of-Cyl]");
    }
    if (sd->status[0] & SNS_STAT1_MESSAGE_TO_OPER) {
        strcat(msgline, " [Operator-Msg]");
    }
    if (sd->status[0] & SNS_STAT1_NO_REC_FOUND) {
        strcat(msgline, " [No-Record-Found]");
    }
    if (sd->status[0] & SNS_STAT1_FILE_PROTECTED) {
        strcat(msgline, " [File-Protected]");
    }
    if (sd->status[0] & SNS_STAT1_WRITE_INHIBITED) {
        strcat(msgline, " [Write-Inhibited]");
    }
    if (sd->status[0] & SNS_STAT1_IMPRECISE_END) {
        strcat(msgline, " [Imprecise-Ending]");
    }

    if (sd->status[1] & SNS_STAT2_REQ_INH_WRITE) {
        strcat(msgline, " [Req-Inhibit-Write]");
    }
    if (sd->status[1] & SNS_STAT2_CORRECTABLE) {
        strcat(msgline, " [Correctable-Data-Check]");
    }
    if (sd->status[1] & SNS_STAT2_FIRST_LOG_ERR) {
        strcat(msgline, " [First-Error-Log]");
    }
    if (sd->status[1] & SNS_STAT2_ENV_DATA_PRESENT) {
        strcat(msgline, " [Env-Data-Present]");
    }
    if (sd->status[1] & SNS_STAT2_IMPRECISE_END) {
        strcat(msgline, " [Imprecise-End]");
    }
    puts(msgline);

    printf("    Residual Count     = 0x%X\n", sd->res_count);
    printf("    Phys Drive ID      = 0x%X\n", sd->phys_drive_id);
    printf("    low cyl address    = 0x%X\n", sd->low_cyl_addr);
    printf("    head addr & hi cyl = 0x%X\n", sd->head_high_cyl_addr);
    printf("    format/message     = 0x%X\n", sd->fmt_msg);
    printf("    fmt-dependent[0-7] = 0x%llX\n", sd->fmt_dependent_info[0]);
    printf("    fmt-dependent[8-15]= 0x%llX\n", sd->fmt_dependent_info[1]);
    printf("    prog action code   = 0x%X\n", sd->program_action_code);
    printf("    Configuration info = 0x%X\n", sd->config_info);
    printf("    mcode / hi-cyl     = 0x%X\n", sd->mcode_hicyl);
    printf("    cyl & head addr [0]= 0x%X\n", sd->cyl_head_addr[0]);
    printf("    cyl & head addr [1]= 0x%X\n", sd->cyl_head_addr[1]);
    printf("    cyl & head addr [2]= 0x%X\n", sd->cyl_head_addr[2]);
}

static void print_irb_err(Irb *irb)
{
    uint64_t this_ccw = *(uint64_t *)u32toptr(irb->scsw.cpa);
    uint64_t prev_ccw = *(uint64_t *)u32toptr(irb->scsw.cpa - 8);
    char msgline[256];

    puts("Interrupt Response Block Data:");

    strcat(msgline, "    Function Ctrl :");
    if (irb->scsw.ctrl & SCSW_FCTL_START_FUNC) {
        strcat(msgline, " [Start]");
    }
    if (irb->scsw.ctrl & SCSW_FCTL_HALT_FUNC) {
        strcat(msgline, " [Halt]");
    }
    if (irb->scsw.ctrl & SCSW_FCTL_CLEAR_FUNC) {
        strcat(msgline, " [Clear]");
    }
    puts(msgline);

    msgline[0] = '\0';
    strcat(msgline, "    Activity Ctrl :");
    if (irb->scsw.ctrl & SCSW_ACTL_RESUME_PEND) {
        strcat(msgline, " [Resume-Pending]");
    }
    if (irb->scsw.ctrl & SCSW_ACTL_START_PEND) {
        strcat(msgline, " [Start-Pending]");
    }
    if (irb->scsw.ctrl & SCSW_ACTL_HALT_PEND) {
        strcat(msgline, " [Halt-Pending]");
    }
    if (irb->scsw.ctrl & SCSW_ACTL_CLEAR_PEND) {
        strcat(msgline, " [Clear-Pending]");
    }
    if (irb->scsw.ctrl & SCSW_ACTL_CH_ACTIVE) {
        strcat(msgline, " [Channel-Active]");
    }
    if (irb->scsw.ctrl & SCSW_ACTL_DEV_ACTIVE) {
        strcat(msgline, " [Device-Active]");
    }
    if (irb->scsw.ctrl & SCSW_ACTL_SUSPENDED) {
        strcat(msgline, " [Suspended]");
    }
    puts(msgline);

    msgline[0] = '\0';
    strcat(msgline, "    Status Ctrl :");
    if (irb->scsw.ctrl & SCSW_SCTL_ALERT) {
        strcat(msgline, " [Alert]");
    }
    if (irb->scsw.ctrl & SCSW_SCTL_INTERMED) {
        strcat(msgline, " [Intermediate]");
    }
    if (irb->scsw.ctrl & SCSW_SCTL_PRIMARY) {
        strcat(msgline, " [Primary]");
    }
    if (irb->scsw.ctrl & SCSW_SCTL_SECONDARY) {
        strcat(msgline, " [Secondary]");
    }
    if (irb->scsw.ctrl & SCSW_SCTL_STATUS_PEND) {
        strcat(msgline, " [Status-Pending]");
    }
    puts(msgline);

    msgline[0] = '\0';
    strcat(msgline, "    Device Status :");
    if (irb->scsw.dstat & SCSW_DSTAT_ATTN) {
        strcat(msgline, " [Attention]");
    }
    if (irb->scsw.dstat & SCSW_DSTAT_STATMOD) {
        strcat(msgline, " [Status-Modifier]");
    }
    if (irb->scsw.dstat & SCSW_DSTAT_CUEND) {
        strcat(msgline, " [Ctrl-Unit-End]");
    }
    if (irb->scsw.dstat & SCSW_DSTAT_BUSY) {
        strcat(msgline, " [Busy]");
    }
    if (irb->scsw.dstat & SCSW_DSTAT_CHEND) {
        strcat(msgline, " [Channel-End]");
    }
    if (irb->scsw.dstat & SCSW_DSTAT_DEVEND) {
        strcat(msgline, " [Device-End]");
    }
    if (irb->scsw.dstat & SCSW_DSTAT_UCHK) {
        strcat(msgline, " [Unit-Check]");
    }
    if (irb->scsw.dstat & SCSW_DSTAT_UEXCP) {
        strcat(msgline, " [Unit-Exception]");
    }
    puts(msgline);

    msgline[0] = '\0';
    strcat(msgline, "    Channel Status :");
    if (irb->scsw.cstat & SCSW_CSTAT_PCINT) {
        strcat(msgline, " [Program-Ctrl-Interruption]");
    }
    if (irb->scsw.cstat & SCSW_CSTAT_BADLEN) {
        strcat(msgline, " [Incorrect-Length]");
    }
    if (irb->scsw.cstat & SCSW_CSTAT_PROGCHK) {
        strcat(msgline, " [Program-Check]");
    }
    if (irb->scsw.cstat & SCSW_CSTAT_PROTCHK) {
        strcat(msgline, " [Protection-Check]");
    }
    if (irb->scsw.cstat & SCSW_CSTAT_CHDCHK) {
        strcat(msgline, " [Channel-Data-Check]");
    }
    if (irb->scsw.cstat & SCSW_CSTAT_CHCCHK) {
        strcat(msgline, " [Channel-Ctrl-Check]");
    }
    if (irb->scsw.cstat & SCSW_CSTAT_ICCHK) {
        strcat(msgline, " [Interface-Ctrl-Check]");
    }
    if (irb->scsw.cstat & SCSW_CSTAT_CHAINCHK) {
        strcat(msgline, " [Chaining-Check]");
    }
    puts(msgline);

    printf("    cpa= 0x%X\n", irb->scsw.cpa);
    printf("    prev_ccw= 0x%llX\n", prev_ccw);
    printf("    this_ccw= 0x%llX\n", this_ccw);
}

/*
 * Handles executing ssch, tsch and returns the irb obtained from tsch.
 * Returns 0 on success, -1 if unexpected status pending and we need to retry,
 * otherwise returns condition code from ssch/tsch for error cases.
 */
static int __do_cio(SubChannelId schid, uint32_t ccw_addr, int fmt, Irb *irb)
{
    /*
     * QEMU's CIO implementation requires prefetch and 64-bit idaws. We
     * allow all paths.
     */
    CmdOrb orb = {
        .fmt = fmt,
        .pfch = 1,
        .c64 = 1,
        .lpm = 0xFF,
        .cpa = ccw_addr,
    };
    int rc;

    IPL_assert(fmt == 0 || fmt == 1, "Invalid ccw format");

    /* ccw_addr must be <= 24 bits and point to at least one whole ccw. */
    if (fmt == 0) {
        IPL_assert(ccw_addr <= 0xFFFFFF - 8, "Invalid ccw address");
    }

    rc = ssch(schid, &orb);
    if (rc == 1 || rc == 2) {
        /* Subchannel status pending or busy. Eat status and ask for retry. */
        tsch(schid, irb);
        return -1;
    }
    if (rc) {
        printf("ssch failed with cc= 0x%x\n", rc);
        return rc;
    }

    consume_io_int();

    /* collect status */
    rc = tsch(schid, irb);
    if (rc) {
        printf("tsch failed with cc= 0x%X\n", rc);
    }

    return rc;
}

/*
 * Executes a channel program at a given subchannel. The request to run the
 * channel program is sent to the subchannel, we then wait for the interrupt
 * signaling completion of the I/O operation(s) performed by the channel
 * program. Lastly we verify that the i/o operation completed without error and
 * that the interrupt we received was for the subchannel used to run the
 * channel program.
 *
 * Note: This function assumes it is running in an environment where no other
 * cpus are generating or receiving I/O interrupts. So either run it in a
 * single-cpu environment or make sure all other cpus are not doing I/O and
 * have I/O interrupts masked off. We also assume that only one device is
 * active (generating i/o interrupts).
 *
 * Returns non-zero on error.
 */
int do_cio(SubChannelId schid, uint16_t cutype, uint32_t ccw_addr, int fmt)
{
    Irb irb = {};
    SenseDataEckdDasd sd;
    int rc, retries = 0;

    while (true) {
        rc = __do_cio(schid, ccw_addr, fmt, &irb);

        if (rc == -1) {
            retries++;
            continue;
        }
        if (rc) {
            /* ssch/tsch error. Message already reported by __do_cio */
            break;
        }

        if (!irb_error(&irb)) {
            break;
        }

        /*
         * Unexpected unit check, or interface-control-check. Use sense to
         * clear (unit check only) then retry.
         */
        if ((unit_check(&irb) || iface_ctrl_check(&irb)) && retries <= 2) {
            if (unit_check(&irb)) {
                basic_sense(schid, cutype, &sd, sizeof(sd));
            }
            retries++;
            continue;
        }

        printf("cio device error\n");
        printf("  ssid  0x%X\n", schid.ssid);
        printf("  cssid 0x%X\n", schid.cssid);
        printf("  sch_no 0x%X\n", schid.sch_no);
        printf("  ctrl-unit type 0x%X\n", cutype);
        printf("\n");
        print_irb_err(&irb);
        if (cutype == CU_TYPE_DASD_3990 || cutype == CU_TYPE_DASD_2107 ||
            cutype == CU_TYPE_UNKNOWN) {
            if (!basic_sense(schid, cutype, &sd, sizeof(sd))) {
                print_eckd_dasd_sense_data(&sd);
            }
        }
        rc = -1;
        break;
    }

    return rc;
}