/*
 *  CCW device SENSE ID I/O handling.
 *
 *    Copyright IBM Corp. 2002, 2009
 *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
 *               Martin Schwidefsky <schwidefsky@de.ibm.com>
 *               Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
 */

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <asm/ccwdev.h>
#include <asm/setup.h>
#include <asm/cio.h>
#include <asm/diag.h>

#include "cio.h"
#include "cio_debug.h"
#include "device.h"
#include "io_sch.h"

#define SENSE_ID_RETRIES        256
#define SENSE_ID_TIMEOUT        (10 * HZ)
#define SENSE_ID_MIN_LEN        4
#define SENSE_ID_BASIC_LEN      7

/**
 * diag210_to_senseid - convert diag 0x210 data to sense id information
 * @senseid: sense id
 * @diag: diag 0x210 data
 *
 * Return 0 on success, non-zero otherwise.
 */
static int diag210_to_senseid(struct senseid *senseid, struct diag210 *diag)
{
        static struct {
                int class, type, cu_type;
        } vm_devices[] = {
                { 0x08, 0x01, 0x3480 },
                { 0x08, 0x02, 0x3430 },
                { 0x08, 0x10, 0x3420 },
                { 0x08, 0x42, 0x3424 },
                { 0x08, 0x44, 0x9348 },
                { 0x08, 0x81, 0x3490 },
                { 0x08, 0x82, 0x3422 },
                { 0x10, 0x41, 0x1403 },
                { 0x10, 0x42, 0x3211 },
                { 0x10, 0x43, 0x3203 },
                { 0x10, 0x45, 0x3800 },
                { 0x10, 0x47, 0x3262 },
                { 0x10, 0x48, 0x3820 },
                { 0x10, 0x49, 0x3800 },
                { 0x10, 0x4a, 0x4245 },
                { 0x10, 0x4b, 0x4248 },
                { 0x10, 0x4d, 0x3800 },
                { 0x10, 0x4e, 0x3820 },
                { 0x10, 0x4f, 0x3820 },
                { 0x10, 0x82, 0x2540 },
                { 0x10, 0x84, 0x3525 },
                { 0x20, 0x81, 0x2501 },
                { 0x20, 0x82, 0x2540 },
                { 0x20, 0x84, 0x3505 },
                { 0x40, 0x01, 0x3278 },
                { 0x40, 0x04, 0x3277 },
                { 0x40, 0x80, 0x2250 },
                { 0x40, 0xc0, 0x5080 },
                { 0x80, 0x00, 0x3215 },
        };
        int i;

        /* Special case for osa devices. */
        if (diag->vrdcvcla == 0x02 && diag->vrdcvtyp == 0x20) {
                senseid->cu_type = 0x3088;
                senseid->cu_model = 0x60;
                senseid->reserved = 0xff;
                return 0;
        }
        for (i = 0; i < ARRAY_SIZE(vm_devices); i++) {
                if (diag->vrdcvcla == vm_devices[i].class &&
                    diag->vrdcvtyp == vm_devices[i].type) {
                        senseid->cu_type = vm_devices[i].cu_type;
                        senseid->reserved = 0xff;
                        return 0;
                }
        }

        return -ENODEV;
}

/**
 * diag_get_dev_info - retrieve device information via diag 0x210
 * @cdev: ccw device
 *
 * Returns zero on success, non-zero otherwise.
 */
static int diag210_get_dev_info(struct ccw_device *cdev)
{
        struct ccw_dev_id *dev_id = &cdev->private->dev_id;
        struct senseid *senseid = &cdev->private->senseid;
        struct diag210 diag_data;
        int rc;

        if (dev_id->ssid != 0)
                return -ENODEV;
        memset(&diag_data, 0, sizeof(diag_data));
        diag_data.vrdcdvno      = dev_id->devno;
        diag_data.vrdclen       = sizeof(diag_data);
        rc = diag210(&diag_data);
        CIO_TRACE_EVENT(4, "diag210");
        CIO_HEX_EVENT(4, &rc, sizeof(rc));
        CIO_HEX_EVENT(4, &diag_data, sizeof(diag_data));
        if (rc != 0 && rc != 2)
                goto err_failed;
        if (diag210_to_senseid(senseid, &diag_data))
                goto err_unknown;
        return 0;

err_unknown:
        CIO_MSG_EVENT(0, "snsid: device 0.%x.%04x: unknown diag210 data\n",
                      dev_id->ssid, dev_id->devno);
        return -ENODEV;
err_failed:
        CIO_MSG_EVENT(0, "snsid: device 0.%x.%04x: diag210 failed (rc=%d)\n",
                      dev_id->ssid, dev_id->devno, rc);
        return -ENODEV;
}

/*
 * Initialize SENSE ID data.
 */
static void snsid_init(struct ccw_device *cdev)
{
        cdev->private->flags.esid = 0;
        memset(&cdev->private->senseid, 0, sizeof(cdev->private->senseid));
        cdev->private->senseid.cu_type = 0xffff;
}

/*
 * Check for complete SENSE ID data.
 */
static int snsid_check(struct ccw_device *cdev, void *data)
{
        struct cmd_scsw *scsw = &cdev->private->irb.scsw.cmd;
        int len = sizeof(struct senseid) - scsw->count;

        /* Check for incomplete SENSE ID data. */
        if (len < SENSE_ID_MIN_LEN)
                goto out_restart;
        if (cdev->private->senseid.cu_type == 0xffff)
                goto out_restart;
        /* Check for incompatible SENSE ID data. */
        if (cdev->private->senseid.reserved != 0xff)
                return -EOPNOTSUPP;
        /* Check for extended-identification information. */
        if (len > SENSE_ID_BASIC_LEN)
                cdev->private->flags.esid = 1;
        return 0;

out_restart:
        snsid_init(cdev);
        return -EAGAIN;
}

/*
 * Process SENSE ID request result.
 */
static void snsid_callback(struct ccw_device *cdev, void *data, int rc)
{
        struct ccw_dev_id *id = &cdev->private->dev_id;
        struct senseid *senseid = &cdev->private->senseid;
        int vm = 0;

        if (rc && MACHINE_IS_VM) {
                /* Try diag 0x210 fallback on z/VM. */
                snsid_init(cdev);
                if (diag210_get_dev_info(cdev) == 0) {
                        rc = 0;
                        vm = 1;
                }
        }
        CIO_MSG_EVENT(2, "snsid: device 0.%x.%04x: rc=%d %04x/%02x "
                      "%04x/%02x%s\n", id->ssid, id->devno, rc,
                      senseid->cu_type, senseid->cu_model, senseid->dev_type,
                      senseid->dev_model, vm ? " (diag210)" : "");
        ccw_device_sense_id_done(cdev, rc);
}

/**
 * ccw_device_sense_id_start - perform SENSE ID
 * @cdev: ccw device
 *
 * Execute a SENSE ID channel program on @cdev to update its sense id
 * information. When finished, call ccw_device_sense_id_done with a
 * return code specifying the result.
 */
void ccw_device_sense_id_start(struct ccw_device *cdev)
{
        struct subchannel *sch = to_subchannel(cdev->dev.parent);
        struct ccw_request *req = &cdev->private->req;
        struct ccw1 *cp = cdev->private->iccws;

        CIO_TRACE_EVENT(4, "snsid");
        CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
        /* Data setup. */
        snsid_init(cdev);
        /* Channel program setup. */
        cp->cmd_code    = CCW_CMD_SENSE_ID;
        cp->cda         = (u32) (addr_t) &cdev->private->senseid;
        cp->count       = sizeof(struct senseid);
        cp->flags       = CCW_FLAG_SLI;
        /* Request setup. */
        memset(req, 0, sizeof(*req));
        req->cp         = cp;
        req->timeout    = SENSE_ID_TIMEOUT;
        req->maxretries = SENSE_ID_RETRIES;
        req->lpm        = sch->schib.pmcw.pam & sch->opm;
        req->check      = snsid_check;
        req->callback   = snsid_callback;
        ccw_request_start(cdev);
}