/*
 *  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);
}